CD63 and acute myeloid leukemia: In our group of patients, we found a significant decrease in activation markers such as p-selectin and granulophysin, associated with the decrease in GpIb and β3 integrin, demonstrating that, in AML, there could be multiple defects of signalling transduction, leading to defects of adhesion, aggregation and the secretion of platelets, consequently leading to haemorrhagic syndrome independent of the number of platelets in the peripheral blood.