...proliferation assays were performed by using different doses of compound on NIH3T3 cells transformed by RET/C634Y or RET/M918T mutants...At 6 days, 5 nM ponatinib strongly reduced cell proliferation driven by RET/C634Y (from 24 × 103% [95% CI = 19 × 103%–29 × 103%] to 16 × 103% [95% CI = 13 × 103%–19 × 103%]) and RET/M918T (from 30 × 103% [95% CI = 29 × 103%–31 × 103%] to 19.5 × 103% [95% CI = 17.5 × 103%–21.5 × 103%]) (P < .001).