TPH1 and Familial prostate cancer: In support of this, we analyzed the RNA-Seq data from the Beltran’s prostate cancer dataset (25) and found that the 5-HT biosynthesis enzyme tryptophan hydroxylase 1 (TPH1) was markedly upregulated in NEPC compared with other PCa subtypes (Supplemental Figure 1C; supplemental material available online with this article; https://doi.org/10.1172/JCI183544DS1).