CFTR and familial long QT syndrome: These findings are comparable to the lysosomal degradation of other misfolded plasma membrane proteins that escape the ERAD pathway, such as certain mutant Cl− channels (i.e., cystic fibrosis transmembrane regulator, CFTR) responsible for cystic fibrosis [78, 79] and defective K+ channels (i.e., human ether-a-go-go-related, hERG) that cause long QT syndrome 2 [80], and highlight the importance of a secondary peripheral quality control mechanism to eliminate the accumulation of improperly folded proteins.