CD274 and esophageal squamous cell carcinoma: The results of PSA indicated that when the price of nivolumab and ipilimumab at 20% price, the cost-effective probability of nivolumab plus ipilimumab improved from 0% to 40.44% and 86.38% in overall and PD-L1-positive advanced ESCC patients, respectively, otherwise chemotherapy was dominant at a WTP threshold of $38,351.20/QALY.