CD4 and Autoimmunity: Although up to fourfold increased numbers of central and effector-memory CD4+ Tconv and CD8+ T cells were found in LN of 10-wk-old Carmil2QECd28−/− mice as compared to age-matched WT mice, cohorts of Carmil2QECd28−/− mice maintained over a period of 50 wk under specific pathogen-free conditions showed no obvious sign of autoimmune pathologies and had weight gain and survival rate comparable to age-matched WT mice.