Although the effect of hyperglycemia on the anti-tumor effects induced by PD-1 antibody treatment should be examined in mice with other tumors in the future, our data showing no changes in the frequency of these T cell subsets suggests that impaired migration, rather than alterations in effector T cell subsets, causes the reduced anti-tumor efficacy of anti-PD-1 antibody treatment in STZ-induced diabetic mice. The gene discussed is PDCD1; the disease is neoplasm.