Description: The 20LJS09 monoclonal antibody reacts with human interleukin (IL)-17AF heterodimer. This antibody specifically reacts with this heterodimer and has no reactivity for IL-17A or IL-17F homodimers. IL-17A and IL-17F are well-characterized homodimeric cytokines secreted by T helper 17 (Th17) cells, gamma-delta T cells and several subsets of innate lymphoid cells. Somewhat less appreciated, IL-17A and IL-17F subunits can also form the heterodimer, IL-17AF. Together, these three dimers signal through the IL-17RA/IL-17RC receptor complex to mediate immune responses at mucosal interfaces and are found at lesion sites in inflammatory bowel disease, asthma, atopic dermatitis and rheumatoid arthritis.