Several studies linked AML and MDS to chemotherapeutic agents,10,27,28 radiation treatment,29,30,31 and supportive treatment with granulocyte colony-stimulating factor.4 These results are consistent with other available data showing a 21⁄2-fold to 31⁄2-fold increased risk of AML.9,27,30 Our estimates of a 5-fold increase in MDS risk were slightly higher compared with data reporting a 3.7-fold increased risk9; MDS risk might likely be underreported in other data sets.32 Here, CSF3 is linked to acute myeloid leukemia.