To validate these findings in CLL cells, where low intracellular ROS are causally associated to their p66Shc expression defect (Patrussi et al., 2019; Tatangelo et al., 2022), leukemic cells isolated from CLL patients were transiently nucleofected with vectors encoding either wild-type p66Shc (p66) or the ROS defective p66ShcQQ mutant (p66QQ) (Figure 5E) and PD-L1 expression was assessed by flow cytometry 24 h after transfection. This evidence concerns the gene CD274 and B-cell chronic lymphocytic leukemia.