CD4 and keratoconus: Although KC;iASPPΔ8/Δ8 pancreas-infiltrating CD4+ T cells expressed increased CD44 (p = 5.5 × 10–3), they also had 2.3-fold increased expression of PD-1H (p = 5.3 × 10–3, Fig. 4E), suggesting that they might be subject to immunosuppression.