The role of the MEK/ERK pathway in PML/RARalpha expression, differentiation, proliferation and apoptosis in APL cells was analysed using specific MEK inhibitors.     ///    "The aberrant function of PML/RARalpha, together with the constitutive activation of the mitogen-activated protein/extracellular signal-regulated kinase (MEK/ERK) signalling pathway, regulates the ability of haematopoietic cells to proliferate, differentiate, and escape from apoptotic episodes. "    ///    "Taken together, our data suggest a new role of MEK/ERK pathway in the pathogenesis of APL, thus supporting the use of MEK/ERK inhibitors as an efficient therapeutic strategy for this haematological malignancy.. "    ///    "The blockade of MEK/ERK pathway resulted in caspase-dependent degradation of PML/RARalpha, and attenuation of the cell differentiation induction. "    ///    "To our knowledge, this is the first report to show that PML/RARalpha was suppressed by MEK/ERK inhibition, through a mechanism dependent on caspase activation. "