Mechanistically different correctors and potentiators, such as those described here, amplifiers that stabilize mRNA levels, such as PTI-428 [15], inhibitors of nonsense-mediated decay for mutations such as W1282X [17,40], and new compounds with unique mechanisms of action may be required in different combinations to address many of the remaining several hundred clinically relevant CFTR mutations that account for 5–10% of CF patients not eligible for KALYDECOTM or TRIKAFTATM. The gene discussed is CFTR; the disease is cystic fibrosis.