TIGIT engages with CD155/CD112 on tumor cells and APCs, inhibiting T-cell activity, and anti-TIGIT mAbs like vibostolimab demonstrate modest ORRs of 5–7% either as monotherapy or in combination with pembrolizumab in anti-PD-1-refractory NSCLC. The gene discussed is PDCD1; the disease is non-small cell lung carcinoma.