CXCL1 and infection: By 7 dpi, the SFV + IAV coinfection had induced significantly higher levels of chemokines keratinocyte‐derived chemokine [KC; also known as C–X–C motif chemokine ligand 1 (CXCL1)], monocyte chemoattractant protein‐1 (MCP‐1; also known as CCL2) and regulated upon activation, normal T‐cell expressed and secreted (RANTES; also known as CCL5) in the lungs compared with IAV‐ and SFV‐only infection and levels of IFNγ and interleukin‐6 were now higher in the coinfected mice than in the IAV‐infected mice, a switch relative to day 3 (Figure 2c).