In the TBS set, the methylation levels of cg11754974, cg13828440, and cg18637238 were higher in BC with stage 0/I or II than those in stage III/IV, and there was no obvious difference regarding tumor size, age, lymph node metastasis status, ER status, PR status, HER2 status, or Ki67 levels (Fig. 3c). The gene discussed is ERBB2; the disease is breast cancer.