KRIT1 and posterior cortical atrophy: Notably, suppression of CCM1 further upregulated the basal level of Y593-phosphorylated DDX5 in all cell lines grown in serum-free medium, similarly to what was observed in scramble control cells stimulated with WNT or PDGF (Figure 6C,D), indicating that the CCM1-mediated regulation of Y593 phosphorylation was not limited to PCa cells.