Le Dieu and coworkers identified higher amounts of clusters of differentiation 3+ (CD3) T cells and CD8+ T cells in the peripheral blood (PB) of AML patients as well as a higher expression of activation markers, such as CD25 and CD69, concurrent with a higher expression of memory markers, thus concluding that in AML, the immune system is in a primed and activated state [13]. The gene discussed is CD69; the disease is acute myeloid leukemia.