The most pronounced associations were observed in cervical squamous cell carcinoma (CESC), bladder cancer (BLCA), breast cancer (BRCA), and gastric adenocarcinoma (STAD), as depicted in Figure 4B. Specifically, in CESC (r = −0.44, p = 0), BLCA (r = −0.41, p = 0), BRCA (r = −0.31, p = 5.2 × 10−17), and STAD (r = −0.37, p = 3.9 × 10−13), BAP31 methylation exhibited a negative correlation with BAP31 mRNA expression, as illustrated in Figure 4C–F. The gene discussed is BCAP31; the disease is breast cancer.