FLT3 and acute lymphoblastic leukemia: Of note, although neither simple positivity of RTK-RAS pathway mutations nor co-occurrence of FLT3 and RAS mutations was significantly associated with survival rates (Supplementary Fig. 12a–d), upon stratification by the number of RTK-RAS pathway mutations per case, infants with ≥3 mutations in RTK-RAS pathway showed significantly worse EFS compared with infants without RTK-RAS pathway mutations (log-rank P = 0.028; Fig. 4d), highlighting the importance of accurate detection of subclonal diversity for risk stratification of infant ALL.