CD4 and colitis: Furthermore, in line with our sensitivity analysis and computer simulations, results of our adoptive transfer studies in mice indicate that activation of PPARγ by oral pioglitazone administration favors a switch from Th17 to iTreg in MLN and colonic LP of mice with CD4+ T cell-induced colitis, thereby demonstrating that PPARγ is implicated in the modulation of CD4+ T cell plasticity in vivo.