T-lymphocytes attacking cancer cell, illustration - stock illustration

T lymphocyte cells attacking a cancer cell, computer illustration. T lymphocytes are a type of white blood cell that recognise a specific site (antigen) on the surface of cancer cells or pathogens and bind to it. Some T lymphocytes then signal for other immune system cells to eliminate the cell. The genetic changes that cause a cell to become cancerous lead to the presentation of tumour antigens on the cell's surface.