Patients with the rs397508513 AC genotype (one copy of the CFTR K1060T variant) and cystic fibrosis may respond to ivacaftor treatment. FDA-approved drug labeling information and CPIC guidelines indicate use of ivacaftor in cystic fibrosis patients with at least one copy of a list of 33 CFTR genetic variants, including K1060T. Other genetic and clinical factors may also influence response to ivacaftor.