CHEK1 and non-small cell lung carcinoma: In contrast, experimentally validated targets downstream of Rb including E2F1, E2F2, E2F3, E2F7, WEE1, CHK1 and CARD10 [25,32,33] seem to be less relevant for the regulation of cell cycle progression by miR-15a/16 or miR-34a, at least in NSCLC cells.