Our study is unique because we examined 12 lung cancer cell lines representing all four subtypes, and we used both qPCR and PCA of 12 genes (AMY2A, CDH1, FOXG1, IGSF3, ISL1, MALL, PLAU, RAB25, S100P, SLCO4A1, STMN1, and TGM2). Here, S100P is linked to lung cancer.