With a methylation threshold of 15%, the frequency of methylation in TCGA breast cancers (N=312) was 64.4% for AKR1B1, 67.3% for ALX1, 81.4% for RASSF1A, and 52.2% for TM6SF1. These numbers again stress the importance of methylation of the 4 selected genes/CpG regions in breast carcinogenesis. The gene discussed is AKR1B1; the disease is breast cancer.