The study by Koyama et al. observed, in a mouse model of lung adenocarcinoma, an upregulation of alternative immune checkpoints, particularly TIM-3, in T cells bound to the PD-1 antibody and demonstrated a survival advantage when a TIM-3 blocking antibody was added after PD-1 blockade failed. The gene discussed is PDCD1; the disease is lung adenocarcinoma.