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). This evidence concerns the gene SYK and chronic myelogenous leukemia, BCR-ABL1 positive.