Considering the dichotomous consequence that individual loss of AMPKα1 versus loss of AMPKα2 had for tumor-infiltrating Treg cell–suppressive function, we also evaluated how each AMPKα subunit contributed to Treg cell function during viral pneumonia by challenging Prkaa1fl/flFoxp3YFP–Cre, Prkaa2fl/flFoxp3YFP–Cre, and control mice with intratracheal inoculations of influenza virus. The gene discussed is PRKAA2; the disease is viral pneumonia.