Compared with CRPC adenocarcinoma patients, NK1R expression was significantly upregulated along with the expression of NE marker CgA, SYP, and the genes related to neuroendocrine and nervous system development including MYT1, SRRM4, etc. (referred to as NE-related genes) in CRPC-derived tNEPC patients, while the adenocarcinoma marker AR and AR target genes like KLK3 and ABCC4 were low (Fig. 2A and Fig. S1A). This evidence concerns the gene KLK3 and adenocarcinoma.