CHRM4 and prostate carcinoma: Since we showed that upregulated NGF cannot increase expression of CHRM1 and CHRM3 (Fig. 5e; Supplementary Fig. 5c), this result suggests that NGF–CHRM4 might be a unique signaling pathway involved in neuroendocrine differentiation of prostate cancer that differs from canonical acetylcholine–CHRM pathways.