Tumor-infiltrating lymphocyte (TIL)

Tumor-infiltrating lymphocytes (TILs) are a heterogeneous group of immune cells—primarily T cells and B cells—that migrate from the bloodstream into a tumor's microenvironment[2][5][7]. They include both adaptive and innate lymphocyte populations, such as natural killer (NK) cells, and their abundance and activity correlate with patient prognosis, particularly in solid tumors like melanoma, breast, and colorectal cancers[2][7]. TILs mediate antitumor immune responses via cytotoxic activity and cytokine release, often contributing to tumor cell death and tumor regression. Clinically, high levels of TILs are associated with better outcomes and are used as biomarkers for therapy selection and prognosis[7][6]. Despite their fundamental role, "tumor infiltrating lymphocyte" is not a molecular target or receptor suitable for drug targeting; it is a cell population, not a protein or receptor[2][5][7]. TIL therapy involves isolating a patient's own TILs, expanding them ex vivo, and reinfusing them as cellular immunotherapy for cancers such as advanced melanoma[3][5][1]. Therapeutic challenges include immune exhaustion in the tumor microenvironment and immunosuppressive mechanisms by tumor cells. Clarifications: - "Tumor-infiltrating lymphocyte" is **not** a molecular target (e.g., a receptor, enzyme, transporter) but a cellular population or biological phenomenon. Thus, it is not correct to classify it as a traditional drug target or molecular entity for drug–target interaction mapping[2][5][7]. - The entry should be marked **is_incorrect: true** since the provided name is not a discrete target but describes an immune cell subset. Summary remarks: If you seek information about a specific molecular target or receptor found on TILs (e.g., PD-1, CTLA-4, LAG-3, CD8), those should be named and annotated individually.

Other names

tumor-infiltrating lymphocytesTILs