PTEN and breast cancer: PTEN, phosphatase and tensin homolog, is a highly penetrant tumor suppressor gene, and a pathogenic variant in this gene is associated with up to 65%−85% increased risk of BC.13,20 Pathogenic variants in PTEN gene are commonly found in various tumors, including those of the brain, lungs, breast, liver, pancreas, and prostate.20 Additionally, PTEN mutations are associated with Cowden syndrome, a genetic condition characterized by multiple benign tumor-like growths (hamartomas) and an elevated risk of certain cancers.