We chose to measure the CD7 expression levels in the acute myeloid leukaemia cell lines MOLM-13, KG-1a, and K562; CD7-overexpressing K562 (K562-CD7) cells; and the CD7-positive human T-lymphocyte leukaemia cell line CCRF-CEM. The gene discussed is CD7; the disease is acute myeloid leukemia.