Indeed, mRNA expression of CREB and GRK3 are positively correlated in several widely cited prostate cancer datasets, such as Yu_PCa [66] (GSE6919), Taylor_PCa [67] (GSE21034) and TCGA_PCa (obtained from www.cBioPortal.org [48, 49]), with Pearson correlation coefficients r = 0.36, 0.44 and 0.52, respectively, and P < 0.000001 for all three (Figure 5A). Here, GRK3 is linked to Familial prostate cancer.