ACOD1 and infection: The gene encoding ACOD1, formerly named Irg1, has popped up in screens for IFNγ- and TLR-induced macrophage or dendritic cell (DC) mRNAs even before the introduction of microarrays (18, 19), and was confirmed as a highly induced gene by many studies on the response to macrophage stimulation by bacterial PAMPs or infection (16, 20–22), or activation with type I IFN (10), IFNγ and/or TNF (23, 24) (see Figure 1).