SPAG9 and cancer: To identify the significant differences in methylation sites between cancer and precancerous lesions, the GEO datasets GSE139404 and GSE48684 were selected to validate the key methylation sites, and we found that the methylation of cg04441191 (MAP4), cg05658717(KSR2), cg10698404 (YWHAG), cg17047993 (SPAG9), cg24504843 (CEP135), and cg24531267 (CEP250) sites were significantly different between normal and tumor tissues (Figure 6).