UBE2E3 and colorectal carcinoma: CRY2 over-expression in human CRC samples may be caused by down-regulation of FBXW7, encoding F-box and WD repeat domain containing 7, E3 ubiquitin protein ligase, which binds directly to phosphorylated Thr300 of CRY2 and tags this circadian protein for proteasomal degradation.