IL17D and lung cancer: Induction of IL-17D expression in A549 cells, which also do not endogenously express IL-17D, led to elevated expression of macrophage-related genes such as CCL3, CCL4, and CSF1. Further investigations using an IL-17D knockdown lung cancer cell line (H1155) revealed that IL-17D upregulates the genes related to macrophage-recruitment and polarization through the p38 MAPK signaling pathway (Lin et al., 2022).