NOTCH1 and acute lymphoblastic leukemia: In the BFM (n=301) and GBTL1 ALL-99 (Brazilian) (n=62) pediatric ALL cohort studies, it was shown that in the absence of NOTCH1 mutations PTEN gene variations were associated with poor prognosis, while the DCOG/COALL (German) (n=146) cohort study reported PTEN variations as independent high-risk factors for relapse [10].