Based on the current state of and gaps in the research on applying dCRT+ICI treatment in ESCC (discussed above), the aims of this study are (1) to evaluate whether the addition of PD-L1 as an ICI to dCRT could also improve survival outcomes for patients with inoperable ESCC and (2) to explore the impact of different immunotherapy intervention timings on prognosis. The gene discussed is CD274; the disease is esophageal squamous cell carcinoma.