Remarkably, p38MAPK activation has been involved in PV pathogenesis [68], and its decrease by caspase-3 inhibition, shown here in the PV mouse model, stipulates that p38MAPK could, like cyclins, c-Myc and N-Myc, be dependent on caspase-3 activation in PV. This evidence concerns the gene CASP3 and acquired polycythemia vera.