Moreover, targeting CD47 in a mouse model of esophageal squamous cell cancer not only enhanced proinflammatory responses and increased infiltration of CD8+ T cells within the tumor, but also increased PD-1 and CTLA-4 expression, thus increasing mouse susceptibility to anti-PD-1 and CTLA-4. Here, PDCD1 is linked to esophageal squamous cell carcinoma.