Utilizing gene expression profiles to characterize tumor infiltrating lymphocytes in cancers
With the advancement in immunotherapy and high- throughput technologies, tumor infiltrating lymphocytes (TILs) have become an important research topic in several diseases, especially different cancers. TILs are lymphoid cells, including T-cells and B-cells, that can infiltrate solid tumor cells and trigger immune responses from the individual. Unsurprisingly, the prognostic effects that TILs showed in cancer patients can be traced back to the 1980s (1). At that time, identification of TILs relied on examining the pathology slides of tumor tissues resected from patients; this is still a standard approach to analyze TILs in clinics. However, the labor-intensive nature and associated high costs of this approach make it impractical to use on a large- scale investigation with a large number of patients.