CD4 and Alzheimer disease: Next, to test the importance of Hh signaling in induction of Treg immunoregulatory function in AD in vivo, we compared the ability of CD4+CD25+ (Treg) cells purified from Oxa-treated Gli2ΔN2 or Gli2ΔC2 mice to inhibit AD induction and reduce disease severity and inflammation on adoptive transfer into Oxa-treated WT recipients (Figure 7, G–K).