The Department of Clinical Laboratory at Peking University Cancer Hospital was established in 1976 and has developed into a modern laboratory center supported by cancer diagnosis and treatment. The department currently has a total of 52 staff members, including 47 professional technical personnel and 5 medical support staff. It currently has 2 personnel with senior professional titles (professor-level), 3 with associate senior titles, 24 with intermediate titles, 4 with doctoral degrees, and 11 with master's degrees. The department consists of five sub-specialty laboratories: Clinical Biochemistry, Clinical Immunology, Clinical Hematology & Routine Testing, Clinical Microbiology, and Clinical Molecular Diagnostics. It performs a total of 228 tests, with an annual workload exceeding 1 million items. The implementation of tumor markers and tests related to cancer diagnosis and treatment is consistent with international peers. Adhering to the principle of "patient-centered, quality-assured," the department provides timely and accurate test results for patients and offers scientific laboratory evidence for clinical diagnosis and treatment. The department has established and operates a quality assurance management system covering the entire process (pre-analytical, analytical, and post-analytical) in accordance with the requirements of CNAS-AL02: "Medical Laboratories – Requirements for Quality and Competence." Through the laboratory information system (LIS) backend dashboard, the internal quality control status of all test items can be monitored in real time. Control standards for intra-laboratory test variation and mean fluctuation have been formulated. Online drafting, review, and approval of root cause analysis reports for out-of-control internal quality control results and monthly summary reports for internal quality control are conducted. The department participates in external quality assessment (EQA) programs organized by the National Center for Clinical Laboratories and the Beijing Municipal Clinical Laboratory Center, as well as the Beijing-Tianjin-Hebei-Shandong inter-laboratory result recognition unannounced inspections, with a participation rate of 100%. The pass rate for EQA and unannounced inspections exceeds 99.5%. The department consistently passes the on-site verification for the Beijing-Tianjin-Hebei-Shandong mutual recognition program with excellent results annually. The department is equipped with advanced testing instruments, including biochemical analyzers, immunoassay analyzers, hematology analyzers, blood smear processing systems, coagulation analyzers, urine analyzers, stool analyzers, blood typing analyzers, blood culture systems, antimicrobial susceptibility testing systems, microbial mass spectrometry identification systems, acid-fast bacillus smear reading systems, PCR analyzers, flow cytometers, and automated scanning fluorescence microscopes. Multiple identical types of automated analyzers are connected and combined to replace single-unit analysis, ensuring rapid sample testing and test quality. The department has completed the construction of a smart laboratory information system (LIS). Through the intelligent LIS connected to testing instruments, staff can review test signals and images online, ensuring the quality of result verification. Through the seamless integration of the LIS with the Hospital Information System (HIS), sample workflow is managed using barcode tracking. Real-time information on sample collection, workflow at various nodes, testing, archiving, and disposal can be viewed in the laboratory, blood collection room, and doctor workstation. Sample workflow, handling of unqualified samples, critical value reporting, and infectious disease reporting all achieve closed-loop management. Advanced sample pre-processing and post-processing systems ensure rapid and accurate sample sorting, as well as retrieval and querying after analysis. Test reports are transmitted in PDF image format and archived in real time. Patients can view reports on their mobile devices and, if needed, print test reports via self-service kiosks. The department places great emphasis on controlling turnaround time (TAT) to facilitate patient care. The average TAT for routine blood tests, urinalysis, and stool tests is 1 hour. The average TAT for routine coagulation tests, liver function tests, renal function tests, cardiac injury markers, lipid profiles, blood glucose, electrolytes, thyroid function tests, reproductive hormones, pituitary hormones, cortisol, and tumor markers is 3-4 hours, allowing patients to obtain these test results on the same day. For serum markers of hepatitis B, hepatitis C, syphilis, and HIV, samples collected before 2:00 PM at the main campus and before 12:00 PM at the north campus can yield results on the same day; samples collected after these times will have results available by 11:00 AM the next day. Reports for hepatitis B virus DNA, Epstein-Barr virus DNA, and cytomegalovirus DNA tests are available the next day; reports for hepatitis C virus RNA and high-risk human papillomavirus tests have turnaround times of 2 and 5 working days, respectively. The department actively supports its experts in participating in professional societies and associations to contribute to the development of the field. Department experts hold positions as members, standing committee members, or vice chairpersons in organizations such as the Chinese Medical Association's Laboratory Medicine Branch, the Chinese Anti-Cancer Association's Clinical Laboratory and Companion Diagnostics Committee, the Chinese Hospital Management Association's Clinical Laboratory Management Committee, the China Health Insurance Research Association's Medical Insurance and Medical Technology Committee, the Beijing Medical Association's Laboratory Medicine Branch, the Beijing Medical Education Association's Laboratory Medicine Branch, and the Beijing Clinical Laboratory Quality Improvement Center. The department places great emphasis on training young core staff. Every Tuesday from 12:00 to 13:00 and every Thursday from 16:00 to 17:00, young core staff present "difficult case" analysis reports, "literature" and "research progress" updates, guideline readings, and "department management procedure document" studies. The department regularly organizes national and district/county-level continuing education programs, actively recruits visiting laboratory physicians/technologists and interns from across the country, and actively undertakes undergraduate teaching tasks for the Department of Laboratory Medicine at Peking University Health Science Center. It serves as a master's and doctoral degree program site for Clinical Laboratory Diagnostics at Peking University Health Science Center. The department's primary research focuses on the rational application of tumor markers and monitoring of adverse effects related to anti-tumor therapy. Research areas include: (1) the predictive value of changes in circulating protein tumor marker patterns across different treatment cycles for progression-free survival and overall survival in cancer patients; (2) a multimodal predictive model integrating circulating HER2, HER2-positive cancer cells with pathological and imaging examinations to guide antibody-drug conjugate (ADC) therapy; (3) the predictive value of peritoneal lavage fluid polyploid cytology for postoperative progression-free survival in gastric cancer patients; (4) the use of bone turnover markers combined with imaging and clinical data to predict bone metastases and guide "bone-modifying therapy" (BMT) in patients with bone metastases; (5) tracking hepatitis virus reactivation in cancer patients with positive hepatitis C virus antibodies or past hepatitis B virus infection; (6) tracking the management of adverse effects from immune checkpoint inhibitors. The ultimate goal of the research is to use existing technical methods to solve clinical problems and translate research findings into clinical applications to benefit patients. The department has undertaken or primarily participated in research projects funded by the National High-Tech R&D Program (863 Program), National Key Research and Development Projects, National Natural Science Foundation of China, Beijing Natural Science Foundation, Capital Medical Development Research Fund, and Peking University Medicine+X Fund. Since 2012, the department has published 61 papers in Chinese core journals and 20 papers indexed in SCI. The department will focus on "continuously improving clinical laboratory quality and better serving patients" as its core mission, advancing discipline construction with a focus on translational research; continuously strengthening communication and exchange with clinical departments, actively promoting interdisciplinary collaboration and integration related to laboratory medicine, and exploring new models for the development of laboratory medicine; fully motivating every staff member, cherishing every opportunity for individual and collective development, working diligently, and comprehensively promoting the department's advancement in medical care, research, and education to safeguard patients.