CRTC1 and cystic fibrosis: Altogether, these data show that in CF mice, the diurnal regulation of the AKT-TORC1 nutrient response, but not that of the core circadian clock, gene expression is lost; in Arntl KO mice, the diurnal regulation of the AKT-TORC1 nutrient response is, if anything, increased, whereas circadian clock gene expression is lost.