TP53 and B-cell chronic lymphocytic leukemia: These data were subsequently confirmed in an another study in which CLL patients lacking TP53 expression and displaying aggressive disease exhibit reduced miR-17 and miR-20a level of expression and increased miR-19a, miR-19b-1 and miR-92a-1, whereas miR-18a levels were unchanged, compared to healthy normal controls [44].