Interferons (IFNs) are cytokines with potent anti-neoplastic properties and significant clinical activity in the treatment of myeloproliferative neoplasms (MPNs). The use of pegylated IFN for the treatment of MPNs has been of particular interest, with several clinical trials establishing clinical responses. Here we demonstrate that chromatin assembly factor 1 subunit B (CHAF1B) is overexpressed in MPN patients. Targeted silencing of CHAF1B enhances transcription of IFN-stimulated genes and promotes IFN-dependent anti-neoplastic effects against MPN patient-derived cells. Our findings suggest that targeting CHAF1B in combination with IFN therapy may offer an avenue for the development of effective combination therapies for the treatment of MPNs.