CDKN2A and acute lymphoblastic leukemia: By contrast, several highly recurrent T-ALL genes were less frequently mutated in IF, particularly NOTCH1 (35.4% v 74.6%; P < .001), FBXW7 (2.1% v 25.4%; P < .001), consistent with their previously reported association with good prognosis,20,21 and CDKN2A (50.0% v 78.4%; P < .001).