MAPK8 and acute lymphoblastic leukemia: Inhibition of MAP2K7 was evident in the reduction of downstream phosphorylation of JNK and ATF2 in most T-ALL cell lines (Figure 3A); however, phosphorylation of MAP2K7 was not significantly reduced by 5Z7O, suggesting that 5Z7O may not inhibit the kinase upstream of MAP2K7, whereas Jurkat, Molt3, and KOPTK1 cells showed a reduction of MAP2K7 protein (Figure 3A).