ERG and posterior cortical atrophy: Since an inverse association between SPINK1 expression and AR signaling was observed in three independent PCa cohorts (TCGA-PRAD, MSKCC and ours) (Fig. 1), we examined role of AR signaling in the regulation of SPINK1 using PCa cell lines, 22RV1 (endogenously SPINK1-positive) and androgen responsive VCaP cells (TMPRSS2-ERG fusion positive) (Supplementary Fig. 2a, b).