LYN and myelodysplastic syndrome: Importantly to leukemias, it is not myelosuppressive.9 Apart from its effects on EGFR activity, gefitinib has shown activity against >20 other kinase targets, including Lyn and Syk.10,11 Gefitinib has been shown activity in acute myeloid leukemia (AML), myelodysplastic syndrome (MDS), and acute lymphocytic leukemia (ALL), inducing both differentiation and cell death in vitro.