PRLR and benign prostatic hyperplasia: Immunohistochemistry (IHC) analysis of clinical samples revealed a heterogenous expression of PRLR in PCa tissues (Fig. 1A), and no statistical significance existed between different pathological tissue types including CRPC (median IHC score: 1.5, 0.0–3.4), HNPC (0.5, 0.0–2.0), and BPH (0.5, 0.0–2.0) (Fig. 1B).