ETP-ALL is often referred to as a subtype of T-ALL as it exhibits an immunophenotype analogous to the earliest stages of T-cell development (cytoplasmic CD3+, CD7+; CD8−, CD1a−, CD5weak), and with expression of myeloid and/or stem-cell markers [144,162]. The gene discussed is CD8A; the disease is acute lymphoblastic leukemia.