MMP1 and posterior cortical atrophy: To establish the appropriateness and reliability of employing SPINK1/IL-8 for in vivo SASP measurement, we selectively acquired stromal cells from the primary tissues of PCa patients via LCM, and analyzed the expression of a subset of signature SASP factors, including MMP1, CXCL3, IL-1β, WNT16B, IL-6, and GM-CSF (Supplementary Fig. 8g).