At 8 weeks after transplant, we compared bm12 allograft histopathology between WT and PD-1 Tg recipients, which revealed significantly lower International Society of Heart and Lung Transplantation (ISHLT) rejection grades, myocyte loss, fibrosis, chronic rejection, and vasculitis in cardiac allografts transplanted into the PD-1 Tg mice compared with WT recipients (Supplemental Figure 3, B and C). The gene discussed is PDCD1; the disease is vasculitis.