TLR2 and giardiasis: In addition, macrophages from TLR2−/− mice in vitro showed enhanced production of IL-12 p40, TNF-α, and IL-6 but not IFN-γ, while TLR2−/− mice only showed enhanced production of IL-12 p40 and IFN-γ in vivo in response to Giardia infection.