All images acquired from a STKS analyser or XL flow cytometer with system II software and all photomicrographs were produced in this laboratory. Except where otherwise stated, all flow images are from whole blood techniques. The phenotypes of Leukaemias are described with only positive antigens except where a negative result is relevant. No claim is made that any image is diagnostic in and of itself, or that the image quality is representative of the instruments concerned.