CTLA4 and arthritic joint disease: There is evidence that DCs play a central role in immune therapy with CTLA4-Ig insofar as Ko et al. [14] demonstrated that when CD11c+ DCs from collagen-induced arthritis (CIA) mice were treated with CTLA4-Ig and adoptively transferred into mice with CIA, no arthritis developed in association with an increase of the CD4+CD25+Foxp3+ Treg population.