The percent of acini with low grade PIN lesions moderately increased while the percent of acini with invasive tumor cells decreased in the RER group (Figure 6B), suggesting that blocking TGF-β signaling with RER in the Pten KO mice caused moderate retardation, instead of promotion, of prostate cancer progression from high grade PIN to invasive cancer. Here, TGFB1 is linked to prostate carcinoma.