PDCD1 and neoplasm: Due to the sustained increases of IFNγ noted with the combination of entinostat and NHS-IL12, a follow-up study investigated this combination therapy in TC-1/a9 (HPV E6/E7+), CMT.64 and RVP3 tumor models resistant to PD-1/PD-L1 blockade due to varying MHC-I and APM deficiencies (53) (Figures 3D, E).