KLK3 and cancer: CIZ1 is also reported to interact with p53 downstream target DNA damage-regulated gene 1 (PDRG1), a novel tumor marker that is up-regulated in cancers of colon, rectum, ovary, lung, stomach, breast, and uterus [43,44], and induces the expression of tumor-related genes AKT and PSA/KLK3 [15].