This gene encodes a pro-inflammatory cytokine that is a member of the interleukin-17 family. The encoded protein plays a central role in host defense against diverse pathogens. The encoded protein is produced by activated T-cells and certain cell types of innate immune system. The active protein functions as either a homodimer with other interleukin-17 family members and signals through the interleukin-17 receptor to induce inflammatory cytokine production. Aberrant expression of this gene is associated with autoinflammatory diseases including rheumatoid arthritis, psoriasis and multiple sclerosis. The heterodimer formed by IL17A and IL17F is a ligand for the heterodimeric complex formed by IL17RA and IL17RC.