Remarkably, our present data shows that MEK inhibition strongly enhances the sensitivity of both RAS-wildtype and RAS-mutant MLL-rearranged ALL cells to prednisolone, also further exemplifying the possible value of MEK inhibitors for RAS-mutant, as well as RAS-wildtype, MLL-rearranged infant ALL patients. This evidence concerns the gene KMT2A and acute lymphoblastic leukemia.