Freeze-fracture scanning electron micrograph of a blood vessel that has grown into a melanoma and is providing nourishment to it. Numerous blood cells can be seen within the blood vessel. This is surrounded by the melanoma which is from mouse skin. Horizontal width of image is approximately 230 micrometres. Supplied by S. Gschmeissner, K. Hodivala-Dilke & M. Stone, courtesy of Wellcome Images.