CREB1 and infection: Infection with S. Typhimurium generally stimulates LPS-dependent M1 macrophage profile in murine macrophages (Mifflin et al., 2002) while PGE2 is associated with M2 polarization profiles, for example, via cyclic-AMP responsive element binding (CREB) induction of Krupple-like factor 4 (KLF4) (Broz and Monack, 2011).