They show that the hyperactivation of the PKCd-ULK1-p38 MAPK pathway may enhance the therapeutic response to IFNα treatment in MPN, in that increased expression of ULK1 and p38 MAPK mRNA correlates with haematological responses in a combined cohort of IFNα-treated PV and ET patients. This evidence concerns the gene ULK1 and acquired polycythemia vera.