ARRB2 and benign prostatic hyperplasia: The IHC analysis of clinical samples revealed higher expression of ARRB2, and pERK1/2 in CRPC specimens compared to HNPC and BPH (Fig. 6F), and a positive correlation was found in the expression levels (IHC score) of pSTAT5B, ARRB2 and pERK1/2 (Fig. 6G, H).