PER3 and prostate cancer: Both RORα1 and PER3 are downregulated in prostate cancer specimens and inversely correlated to Wnt signaling.46,54 In the intestine, the circadian clock regulates the rhythmic secretion of Wnt ligands and intestinal stem cells are highly responsive to Wnt activation.62, -64 Thus, it is plausible that a similar mechanism involving circadian regulation of Wnt signaling may also be operative in prostate cells, contributing to the regulation of stemness and tumorigenic properties of prostate cancer cells.