MAPK8 and acute lymphoblastic leukemia: We recently found that the MELK inhibitor OTSSP167 also inhibited MAP2K7 kinase activity at an IC50 of 160 nM and induced cytotoxicity in T-ALL cells at low nanomolar concentrations (IC50 10-57 nM) through inhibition of the MAP2K7-JNK pathway in T-ALL cell lines (57, 65).