To mimic castration-induced neuroendocrine differentiation in vivo, we compared the expression of GRK3 and NE markers between untreated PAC prostate cancer patient-deprived xenograft (PDX) LTL331 and NEPC PDX LTL331R that was derived from LTL331 after relapse from castration [14, 32, 33, 53]. This evidence concerns the gene GRK3 and prostate cancer.