IL17A and psoriasis: CXCR6+ T cells have also been involved in many immune‐related diseases, such as lung infection, inflammatory arthritis, psoriasis, multiple sclerosis and Crohn's disease.[43, 51, 94, 95, 96] It's reported that CXCR6‐deficient mice (6 weeks) demonstrated enhanced host control over Mycobacterium tuberculosis and influenza virus by influencing the kinetics of the inflammatory response.[43] In CXCR6‐deficient mice (80 days), T cells showed impaired cytokine polarization, leading to fewer IL‐17A‐ and IFNγ‐producing cells.