Recent evidence for the reactivation of pre-existing alloreactive T cells in ICI-mediated allograft rejection in a patient with melanoma was provided by Dunlap et al. The authors showed an expansion of circulating alloreactive CD8+ T cell clones that accumulated in the kidney allograft during rejection while receiving anti-PD-1 treatment, but were not present in tumor tissues. Here, PDCD1 is linked to neoplasm.