CFTR and cystic fibrosis: It was shown that two residues on the NBD1 domain of the channel, namely, Ser422 and Ser670, were phosphorylated by CK2; intriguingly, small peptides from Phe508del-CFTR allosterically promote CK2 activity, implying that in CF, where a strong CFTR fragmentation is observed, the activity of the kinase could be upregulated.227,228