AML biopsies prior to treatment divided into three morphology groups. (A) Scatterplot representing the AML biopsies at diagnosis. Biopsies with a ‘low vessel count’ are displayed below the Y-axis reference line (13 microvessels/hpf, group I). The X-axis reference line divides AML biopsies at diagnosis with a ‘high vessel count’ into two subgroups according to the median Chalkley count of 5.4 in AML at diagnosis. Cut-off points are based on previously described results. Samples with a Chalkley count ≤5.4 were defined as ‘angiogenic sprouting’ (group II) and samples with a Chalkley count >5.4 as ‘vessel hyperplasia’ (group III). (B) A representative picture of the three groups is shown.