Flow cytometry analysis of epidermal samples from patients with psoriasis and healthy controls demonstrated that CD8+ T cells in lesional psoriatic skin exhibited markedly increased activation (elevated CD25 and CD69 expression), enhanced effector cytokine production (TNF-α and IFN-γ), and strengthened tissue-resident properties (CD103 and CXCR6) (Figure 6C and Supplemental Figure 6B). This evidence concerns the gene IFNG and psoriasis.