Additionally, PD-1/PD-L1 deficiency aggravated atherosclerosis in LDL receptor-deficient mice, increasing CD4+ and CD8+ T cell numbers within lesions, while agonistic PD-1 antibody treatment reduced atherosclerosis development, decreased IFNγ-producing CD4+ T cells by 23%, and increased atheroprotective IL-10-producing T cells by 47% [13]. The gene discussed is PDCD1; the disease is atherosclerosis.