Indeed, Singh et al. [46] reported that mice injected with vector-transfected PC3 (prostate cancer) cells formed tumors in the prostate glands and metastatic tumors in the liver, spleen, kidney, stomach, lung, lymph nodes, diaphragm, and mesentery but mice injected with PC3 cells transfected with GPR68 developed tumors confined to the prostate gland and that did not metastasize. Here, GPR68 is linked to prostate cancer.