SYP and prostate cancer: Human TMAs were stained for the following markers: luminal or basal epithelial (AR, NKX3.1, CK8, and P63), neuroendocrine (SYP, INSM1, ASCL1, NEUROD1 and FOXA2), cell surface (TROP2 and DLL3), proliferation (Ki-67), as well as other markers of interest from scRNA-seq analyses of prostate cancer GEMMs (YAP1, POU2F3, MYC, SOX2, TFF3, and EZH2) (17, –19) (Fig. 1A and Dataset S1).