AR and prostate cancer: To understand expression patterns of CHRM4 in relation to AR inhibition in prostate cancer, we examined CHRM4 and AR protein expression levels in androgen-dependent prostate cancer cells (LNCaP), CRPC cells (22Rv1 and C4-2), CRPC cells after long periods of AR antagonist/MDV3100 treatment (C4-2-MDVR), AR-negative prostate cancer cells (PC3), and NEPC-like cells (LASCPC01).