KMT2A and acute lymphoblastic leukemia: ALL patients with poor prognosis, such as infant ALL and Ph+ ALL, tend to have poor clinical response to glucocorticoid agonists.[15,16] Recently, some studies found that trametinib displayed powerful anti-leukemic effects against ALL cells with RAS mutation and MLL rearrangement, as MEK inhibition enhances prednisolone sensitivity.[17] In addition, Jones et al[3] supported the use of trametinib as a potential treatment for relapsed ALL.