HMGA1 and posterior cortical atrophy: To compare whether HMGA1 expression was correlated to let-7b in primary human PCa we isolated m(i)RNA of PCa and adjacent benign tissue samples (cohort C) and performed qRT-PCR analyses on let-7b and HMGA1. We utilized 21 pairs of PCa samples in which expression of let-7b was significantly suppressed (≥0.5 cycles) in cancerous compared to benign tissue (Fig. S3).