↓ CD4+ T-cell migration into gut lamina propria without impacting survivability, proliferation, and differentiation in drd5-KO↓ Colitis manifestations with D5 deficient T-cells or CCR9 deficient T-cells↑ ERK1/2 phosphorylation and cAMP accumulation with SKF81297 treatment. Here, MAPK3 is linked to colitis.