In the initial analysis to establish the physiological pattern of CD44 in precursor cells, CD44 expression was screened on CD34 positive UCB precursor cells and also compared to the expression in AML where it was observed that the aberrant expression pattern of CD44 in T-ALL varies from low to intermediate, since normal CD34 positive precursor cells have high expression. This evidence concerns the gene CD44 and acute lymphoblastic leukemia.