T lymphocytes and cancer cell Coloured scanning electron micrograph SEM of two T lymphocyte 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 x at centimetres wide