ABL1 and cancer: Furthermore, upon MEK1/2 inhibition the levels of the Y412 phosphorylated forms of ABL1 were drastically reduced in the cytoplasm while being increased in the nucleus (Fig. 2B); the opposite effects on ABL1Y412 phosphorylation caused by PD in the two subcellular compartments can partly explain the relatively lower fold reduction in ABL1Y412 phosphorylation observed in whole-cell vs. cytoplasmic extracts derived from the same cancer cell samples exposed to PD treatment (Fig. 2A, B).