GAPDH and acute myeloid leukemia: AML cell lines MOLM-13 and OCI-AML3, which were susceptible to trametinib, had elevated MEK levels of 0.1 and 0.16 MEK/GAPDH, while OCI-AML2 and MOLM-16, both unsusceptible to trametinib, had low MEK levels of less than 0.01 MEK/GAPDH.