PROC and gastric cancer: The risk score of each GC case in TCGA was calculated by summing the product of regression coefficient and gene expression, the formula was: Risk score=0.0303*BEX2+0.2731*C1QL2+0.0784*DKK1+0.1297*DRC1+0.1060*GLUD2+0.0773*HCAR1+0.0851*IGFBP1+0.9108*NXPH1+0.0674*PROC+0.1061*SERPINA5+0.0436*SLCO1A2(1)