One ongoing phase II study is testing the effectiveness of PD-1 inhibition with the anti-PD1 antibody Pembrolizumab in advanced MPN, chronic phase (MF-CP), accelerated phase (MPN-AP), or blast phase (MPN-BP) (ClinicalTrials.gov Identifier: NCT03065400). The gene discussed is PDCD1; the disease is myeloproliferative disorder.