We found that AMPKα1/α2–sufficient Treg cells express both Prkaa1 and Prkaa2 in lymph nodes and the lung during viral pneumonia (Supplemental Figure 7, A and B) and that steady-state splenic AMPKα1/α2–deficient Treg cells have downregulated expression of genes activated during influenza A virus infection (37) (Figure 4A). Here, PRKAA2 is linked to viral pneumonia.