Recent Genome Wide Association Studies (GWAS) of patients with prostate cancer have identified a genetic variant of Lemur Tyrosine Kinase 2 (LMTK2) (also called BREK/KPI-2/CRPK/AATYK2), a membrane associated kinase (Fig. 1A) [25, 26], [27, 28] to be strongly associated with prostate cancer (P < 0.0001) [29–32]. Here, LMTK2 is linked to Familial prostate cancer.