This observation indicates that psoriasis patients present an adaptive immune response to S. pyogenes through IL-17A, IL-17F, IL-9, and IFN-γ production (20, 21, 24) and suggests that S. pyogenes modulates the response of the CLA+ T cells that maintain psoriatic lesions, i.e., pyogenes infection has been describe to participate in CPP infection, since higher levels of IgG against S. pyogenes proteins are detected in psoriasis patients in comparison to healthy controls (25). This evidence concerns the gene IL9 and psoriasis.