Based on this scenario, the aim of this study was to investigate CD44 and its isoform CD44v6 in a cohort of T-ALL cases, in order to determine its aberrant antigenic patterns and its association with different cell maturational subtypes, genetic alterations and clinical characteristics, thus contributing to a better understanding of the role of CD44 in the pathogenesis of T-ALL. The gene discussed is CD44; the disease is acute lymphoblastic leukemia.