Although a very large body of research is devoted to the discovery of reliable biomarkers of response to ICI, the only clinically approved biomarker to date for patient selection for immunotherapy is PD-L1 expression in tumor cells measured by immunohistochemistry (IHC), along with EGFR and BRAF mutations and ALK and ROS1 rearrangements [14]. The gene discussed is CD274; the disease is neoplasm.