Upon treatment with the CM from PSC27 cells overexpressing SPINK1 (PSC27SPINK1), we observed significantly increased proliferation of several PCa cell lines including PC3, DU145, LNCaP, and M12 (P < 0.01) (Supplementary Fig. 4b), accompanied by enhanced migration and invasion (Supplementary Fig. 4c–d). Here, SPINK1 is linked to posterior cortical atrophy.