Although no definitive biomarker for ICI response prediction has been established, several have been shown to correlate to positive patient outcomes, including the presence of tumor‐infiltrating lymphocytes (TILs), PD‐L1 positivity, and tumor mutational burden.[10] Tumors with high levels of TILs, especially cluster of differentiation (CD8+) CTLs, are generally associated with a good prognosis.[11] Currently, TILs are assessed from biopsies and subsequent histological staining methods that do not allow for real‐time monitoring.[12]. The gene discussed is CD8A; the disease is neoplasm.