IL17A and pemphigus foliaceus: Clinical studies have identified elevated Th17 cell frequencies and IL-17A concentrations in BALF during acute exacerbations (Wei et al., 2016), with murine models supporting these findings, as evidenced by the observed reduction in the number of inflammatory foci and diminished fibrosis in AE-PF mice with IL-17A deficiency relative to their wild-type counterparts (Chen et al., 2022).