PDCD1 and gastric cancer: In patients with metastatic GC, the second-line therapy, programmed cell death protein 1 (PD-1) inhibitor (selected according to patients’ requirements) in combination with albumin paclitaxel (125 mg/m2, intravenously, days 1 and 8, or 250 mg/m2, intravenously, day 1) and apatinib (250 or 500 mg, orally, days 1–21) every 3 weeks, has demonstrated modest efficacy and safety [51].