CD4 and colitis: Colitis in piroxicam-treated IL-10-/- mice was associated, within the lamina propria, with an increase in the frequencies of CD4+ T lymphocytes producing either IFNγ (Th1), both IFNγ and IL-17 (a feature of colitis-associated Th17) or IL-4 (Th2) as well as FoxP3-expressing regulatory T lymphocytes as compared to untreated IL-10-/- mice (Figure 3a).