For instance, phase I clinical studies are determining tumor-killing efficacy of IBI939, as an anti-TIGIT mAb alone or in combination with Sintilimab (anti-PD-1 mAb) in advanced malignancies (NCT04353830), or AB154, as an anti-TIGIT mAb in combination with Zimberelimab (anti-PD-1 mAb) in solid tumors (NCT03628677). The gene discussed is PDCD1; the disease is neoplasm.