IL17RC (interleukin 17 receptor C) is a coreceptor that mediates IL-17A and IL-17F signaling at the plasma membrane 1. Upon ligand binding, IL-17RC activates AKT and ERK1/2 signaling cascades that converge on mTOR and HIF1α, driving metabolic reprogramming and epithelial wound repair 1. IL-17RC is predominantly involved in mucosal immunity; loss-of-function variants cause autosomal recessive chr3 mucocutaneous candidiasis (CMC), a primary immunodeficiency characterized by susceptibility to Candida infections without systemic immunodeficiency 2. Beyond infection control, IL-17RC expression is dysregulated in multiple pathologies: elevated IL17RC associates with vitiligo severity and disease activity, correlating with cutaneous immune dysregulation 3; IL-17RC expression increases under hypoxic conditions in retinal pigment epithelium and may contribute to choroidal neovascularization 4; and increased IL17RC correlates with poor ovarian cancer survival through IL-17A-mediated mesothelial-mesenchymal transition promoting metastatic dissemination 5. Conversely, IL17RC is downregulated in hypersensitivity pneumonitis fibroblasts, suggesting context-dependent roles in fibrotic disease 6. Notably, IL-17RC does not contribute to IL-17E-mediated neuromodulation of social behaviors, highlighting receptor specificity in brain function 7. Together, IL17RC represents a critical node integrating mucosal immunity, tissue repair, and aberrant inflammation in diverse disease contexts.