CD7 is a transmembrane glycoprotein expressed in T-cells, natural killer cells, thymocytes and progenitors of both lymphoid and myeloid cells. CD7 expression and lack of expression are both useful in differential diagnosis. CD7 is expressed in 30% of AML cases1. CD7 positivity is linked to poor prognosis1, in myeloid malignancies and disease free survival and post-remission survival in AML2. CD7 loss along with cytogenetic abnormalities increases the identification of Aggressive Natural Killer Leukemia (ANKL) from 50% to 75% in a cohort of 20 patients.