False-colour scannning electron micrograph of a T-lymphocyte killer cell (small cell at left), attacking a large cancer tumour cell. The T- lymphocyte, a white blood cell, must make intimate contact with the tumour cell. It does so by recognizing antigens on the tumour’s surface. Following contact the tumour cell undergoes distinct structural changes; loss of microvilli (small projections), perforation & ultimately death. The tumour cell may survive, however, by budding off a number of blebs or blisters (seen here), which form a protective barrier between itself & the lymphocyte, preventing any contact. Magnification: X 2,500 at 35mm size.