To determine if constitutive inhibitory molecule expression had an impact on T cell function, we isolated OT-Is from the organs of MCMV-infected mice (>12 weeks after infection) and stimulated them ex vivo on peptide pulsed DC2.4s (PD-L1+, not shown) in the presence or absence of a PD-L1 blocking antibody. The gene discussed is CD274; the disease is infection.