Ivacaftor treatment of individuals with cystic fibrosis and CFTR gating variants (e.g., G551D; Bompadre et al., 2007; Cai et al., 2006; Gregory et al., 1991; Xu et al., 2014) achieves sustained, long‐term clinical benefit, including a slower decline in lung function and improved nutrition (Volkova et al., 2020). The gene discussed is CFTR; the disease is cystic fibrosis.