The sensitivity and specificity of a single marker for gastric cancer detection in the training set for SDC2 were 40.9 and 93.3%, for TERT were 36.4 and 90.0%, for RASSF2 were 31.8 and 93.3%, for SFRP2 were 22.7 and 90.0%, and for Hb were 27.3 and 90.0%. The gene discussed is GSTM1; the disease is gastric cancer.