CD8+ T cells have been identified as major effector cells that inhibit the PD‐1/PD‐L1 pathway, thus activating an immune response.[53] The infiltration of tumor‐specific CD8+ T cells within tumors is a critical indicator of effective immunotherapy, with IFN‐γ serving as an important biomarker for CD8+ T cell infiltration.[31, 54] Additionally, IL‐2, a key growth factor for T cells, is used to assess T cell proliferation and infiltration. This evidence concerns the gene PDCD1 and neoplasm.