Illustration of T cell white blood cells attacking a lymphoma cell. Lymphomas are malignant (cancerous) growths of white blood cells (lymphocytes). White blood cells are part of the body's immune system and circulate in a clear liquid called lymph. There are many types of lymphoma depending on the cells affected. T lymphocytes, or T cells, are a type of white blood cell and a component of the body's immune system. They recognise a specific site (antigen) on the surface of a pathogen or cancerous cell, bind to it, and attract antibodies or cells to eliminate it.