Consistently, patients whose neoplastic component displayed a mutated IgVH gene configuration or expressed ZAP-70 in less than 20% of cells frequently belonged to the immunophenotypic group characterized by the best prognosis (group I); conversely, patients characterized by B-CLL cells lacking IgVH mutations or with high ZAP-70 expression levels belonged more frequently to the immunophenotypic groups associated with worse prognosis (groups II and III) [17]. Here, ZAP70 is linked to B-cell chronic lymphocytic leukemia.