CXCL10, the ligand of CXCR3, is increased upon infection with different respiratory viruses, including Influenza, SARS-CoV-1 and SARS-CoV-2 (48, 49), allowing for an efficient recruitment of CXCR3+ Tregs to the lung and the site of the effector response. The gene discussed is CXCR3; the disease is infection.