Accumulating research reveals a consistent association between the presence of tumor-infiltrating CD8 + T cells and the clinical efficacy of ICB therapies in cancers, including CRC, esophageal cancer (EC), pancreatic cancer (PCA), and non-small cell lung cancer (NSCLC) (Matsumoto et al. 2016; Huang et al. 2018; Spranger et al. 2015). Here, CD8A is linked to colorectal carcinoma.