MutL homologue 1 (MLH1), mutS homologue 2 (MSH2), mutS 6 (MSH6), postmeiotic segregation increased 2 (PMS2), and epithelial cell adhesion molecule (EPCAM) are the key components of the DNA mismatch repair (MMR) system, deficiency in which accounts for a significant proportion of human cancers by inducing instability in genome (McGrail et al., 2020). The gene discussed is EPCAM; the disease is cancer.