Chromosome 2 open reading frame 40 (C2orf40), also known as esophageal cancer‐related gene 4 (ECRG4), a tumor suppressor, is hypermethylated in cancers such as colorectal carcinoma [86], glioma [86], breast cancer [87], gastric cancer [88], and bladder cancer [89]. The gene discussed is ECRG4; the disease is breast cancer.