Fig. 4.

Main cellular sources and targets of IL-17C in lung inflammatory response. IL-17C is expressed in various cells, including epithelial cells, Th17 cells, CD4⁺ T cells, DCs, and macrophages. It acts on multiple types of cells, including CD4⁺ T cells, macrophages, and neutrophils, playing an important role in lung inflammation. Definitive evidence has not been reported for the role of IL-17C in regulating pulmonary fibrosis. Th17 T helper cell 17, TNF-α tumor necrosis factor-α, IL-1β interleukin-1β, IPF idiopathic pulmonary fibrosis