CD4 and psoriasis: K14/Gpx4 mice also developed signs of psoriasis-associated systemic inflammation — elevated serum proinflammatory cytokines (e.g., IL-6; Figure 4E), an increase of splenic CD4+ and CD8+ T cells, CD4+ T cell infiltration of the hind-paw synovium, neutrophilic infiltration of the liver and the lungs (Supplemental Figure 8, A–D).