The efficacy as chemo-sensitizer agent of the prexasertib on Philadelphia-negative B-/T-ALL cell lines was evaluated combining the Chk1/Chk2 inhibitor with the purine nucleoside antimetabolite clofarabine, which is commonly used in clinical trials for the treatment of young and adult ALL patients [31, 32]. This evidence concerns the gene CHEK2 and acute lymphoblastic leukemia.