IL17B is a pro-inflammatory cytokine member of the IL-17 family that functions through IL-17RB receptor signaling to modulate immune and inflammatory responses across multiple tissues 1. As a homolog of IL-17A, IL17B stimulates release of tumor necrosis factor-alpha and IL-1β from monocytes and activates NF-κB signaling pathways, leading to upregulation of senescence-associated secretory phenotype factors 2. IL17B participates in Th17-mediated immune responses and exhibits tissue-specific effects, showing both protective and pathogenic roles depending on context 3. Clinically, IL17B is implicated in multiple disease states. In cancer, intracellular bacteria-triggered cGAS-STING-IL17B pathway activation redirects neutrophils toward protumor phenotypes, promoting breast cancer metastasis 4, while the IL17B-IL17RB axis contributes to breast cancer tumorigenesis and progression 5. IL17B expression serves as a new biomarker for muscle regeneration in dystrophinopathies, significantly correlating with histological regeneration in Duchenne and Becker muscular dystrophy patients 6. Additionally, IL17B variants associate with Schistosoma mansoni worm burden through Th17 pathway modulation 7, and IL17B likely contributes to spondyloarthritis immunopathogenesis as part of the IL-17 family 8.