CTLA4 and esophageal cancer: For instance, a meta‐analysis which included advanced esophageal cancer patients reported that the pooled incidences of any grade trAEs were 88% for PD‐1 inhibitors alone population, 79.5% for PD‐1 plus cytotoxic T‐lymphocyte‐associated protein 4 (CTLA‐4) inhibitors population, and the incidences of grade three or more trAEs were 24% for PD‐1 inhibitors alone population, 34.2% for PD‐1 plus CTLA‐4 inhibitors population.28