Mutations in genes in the Notch pathway in patients that relapsed included nonsynonymous SNVs (nsSNVs) in CREBBP (n = 3), EP300 (n = 1), MAML2 (n = 1), HDAC2 (n = 1), NOTCH2 (n = 1) and DTX1 (n = 1), all of which are expressed in BCP-ALL (Supplementary Table S5). Here, HDAC2 is linked to acute lymphoblastic leukemia.