To test the efficacy of αPD1-S in vivo we selected the B16OVA melanoma model which exhibits hypersialylationthat suppresses effector T cells and NK cells, promotes regulatoryT cells, is refractory to treatment with αPD1, and benefitsfrom treatments that reduce sialylation.−,  In particular,it has been shown that reducing sialic acids by intratumoral injectionof a sialyltransferase inhibitor, or by geneticknockdown of a CMP-sialic transporter enhances CD8 T cell-mediated control of B16OVA tumors. The gene discussed is CD8A; the disease is melanoma.