APP and neoplasm: To verify the expression of four ARC signature genes in CRC, we examined their expression in two large samples of external datasets, GSE41258 (181 tumor tissue and 46 control tissue samples) and GSE164191 (59 tumor blood and 62 normal blood samples), and found that S100A4, COL3A1, TIMP1, and APP were all highly expressed in CRC compared with controls between CRC and controls in both tissues and blood samples (Figures 8A, B).