,31 M1-MDMs, with superior COX-2/mPGES-1 expression over M2-MDM, possess higher capacities to produce PGE2 upon exposure to bacterial pathogenicity,21 but upon infection with H1N1, the PGE2 levels of IAV-stimulated M2-MDM surpass those of the M1 counterpart. The gene discussed is PTGS2; the disease is infection.