SMN1 and posterior cortical atrophy: Increased expression of extracellular matrix proteins included smooth muscle actin (SMA), type 1 collagen (Col-1), and vimentin in PKP tumors compared to PBP and wild type controls (Fig. 3f), suggesting that KrasG12D activation in prostate epithelium immediately affects surrounding stromal components, demonstrating that our PKP model well recapitulates stromal responses in metastatic human PCA.