CREBBP, defined in the CRISPR screen as the second most significant TSG and induced by FOXO3 (p = 0.003) and PRDM1 (p = 0.009) but unaffected by FOXO1, is an established TSG with both germline and sporadic mutations contributing to B-ALL [44, 45]. Here, FOXO1 is linked to precursor B-cell acute lymphoblastic leukemia.