LYN and B-cell chronic lymphocytic leukemia: Experiments using the pan-SFK inhibitor dasatinib suggest that Lyn is responsible for constitutive phosphorylation of HS1 in CLL cells [142], which makes sense because Lyn is constitutively active [96], but other SFKs such as Lck could be additionally involved because these cells both express Lck [68, 143, 144] and use it for mediating BCR signaling [67].