The pathogenicity of Th17 cells is closely related to autoimmune diseases, and this pathogenicity depends on IL-6, IL-1β, and IL-23.101 Single-cell RNA-sequencing showed that pathogenic Th17 cells showed increased proinflammatory genes such as IL17a, IL17f, and IL23r, and decreased immunomodulatory genes such as IL4, IL10, and Cd5l. This evidence concerns the gene IL4 and autoimmune disease.