LYN and chronic myelogenous leukemia, BCR-ABL1 positive: Dasatinib is normally used to treat chronic myeloid leukemia and is a tyrosine kinase that inhibits the Src family member Abl.15 However, it is also cytotoxic to CLL cells, including ZAP-70+ cells, and it has been suggested that dasatinib is targeting tyrosine kinase Lyn.15 In addition, Syk has been targeted in CLL with the tyrosine kinase inhibitor, R406 (fostamatinib).