To ensure that these phenotypes are not due to an adverse effect of Tppp depletion on CFTR expression or function, we examined CFTR expression in suprachiasmatic nucleus and surrounding tissue from each mouse model as well as CFTR function in primary mouse nasal epithelial cells (MNE) from WT, F508del (CF), and Tppp−/− mice. This evidence concerns the gene CFTR and cystic fibrosis.