For example, virus-specific cytotoxic T lymphocytes (CTLs) are quickly recruited to influenza-infected lungs by a Th1 response, specifically due to the production of IFNγ (72) Two of these Th1-type effector T-cell chemokine receptors are CXCR3 and CX3CR1. This evidence concerns the gene CX3CR1 and influenza.