KLK3 and lung cancer: Prostate cancer is one of the most commonly diagnosed malignancies in men worldwide and ranks 2nd after lung cancer in terms of cancer-related mortality.[1,2] With advances in early detection methods and the widespread use of prostate-specific antigen (PSA) screening, the diagnosis of clinically insignificant, low-risk prostate cancer (LRPCa) has become increasingly common.[3,4] LRPCa is often an indolent disease, and many patients can live with the condition without experiencing significant clinical progression throughout their lifetime.[5,6]