CD40 and B-cell chronic lymphocytic leukemia: The level of cell activation achieved by CD180 ligation was also found to be equivalent, or in some cases superior to the activation achieved with anti-CD40 or rIL-4 (Porakishvili et al. 2011), which are known to robustly induce CLL cell activation and protect from apoptosis (Falco et al. 2018).