In all five PCA models for lung cancer were constructed using the marker expression as variables (CXCL12, CXCR4, CK7, CDH1, CTNNB1, CLDN4, HIF1A, VEGFA, MMP9, MUC16, TGFBR2, TP53, OPN, CDKN2A, and CD44v6) as shown in Fig 3. This evidence concerns the gene CXCL12 and lung cancer.