PTGS2 and melanoma: Similarly, Naoya Maekawa et al. demonstrated in a canine melanoma model that dual blockade of the PD-1/PD-L1 and COX-2/PGE2 pathways augments IL-2 and IFN-γ production by stimulated peripheral blood mononuclear cells, identifying this strategy as a promising means to enhance antitumor immunity in dogs [39].