Cancer cell and T lymphocytes, SEM - stock photo

T lymphocytes and cancer cell. Coloured scanning electron micrograph (SEM) of T lymphocyte cells (smaller round cells) attached to a cancer cell. T lymphocytes are a type of white blood cell and one of the components of the bodys immune system. They 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. Cytotoxic T lymphocytes eliminate the cell themselves by releasing a protein that forms pores in the cells membrane. The genetic changes that cause a cell to become cancerous lead to the presentation of tumour antigens on the cells surface. Magnification: x2500 at 10 centimetres wide.