In a recent study, a research team from Nagoya University School of Medicine in Japan found that stromal cell derived factor 4 (SDF-4) protein is a reliable tumor marker with an accuracy of nearly 90% in detecting gastric cancer. At present, the tumor markers used in blood testing methods for detecting cancers such as gastric cancer, colorectal cancer and breast cancer include CEA and CA19-9, which cannot accurately detect all cancers. In addition, other markers also have drawbacks such as expensive measurement costs or invasive testing methods. Researchers investigated the proteins secreted by cancer cells and identified SDF-4 as a potential candidate marker. When they measured the concentration of SDF-4 in blood samples from cancer patients and healthy individuals, they found an increase in SDF-4 levels in cancer samples. Blood samples from cancer patients included samples from the stomach, esophagus, colon, rectum, pancreas, breast, and liver. The sensitivity and specificity of cancer diagnosis are very important. To what extent sensitivity testing can detect the patient's disease; And specificity indicates the possibility of testing patients for a certain disease. By testing the protein SDF-4, the research team found that its sensitivity was 89% and specificity was 99%, surpassing the sensitivity of traditional tumor markers in identifying cancer patients (CEA only 13%; CA19-9 only 17%). In addition, the research team also found high levels of protein SDF-4 in samples of stage I gastric cancer patients, indicating that doctors may use it to detect cancer at the onset of symptoms. Liu Xia (Lixin She)