Active Motif's KG-1 nuclear extract was prepared from cell cultures of the human myeloblast KG-1 cell line. The KG-1 cell line was derived from a bone marrow aspirate of a 59 year old Caucasian male patient with erythroleukemia that evolved into acute myelogenous leukemia. These cells spontaneously differentiate to granulocyte, dendritic, and macrophage cells and are therefore commonly used in research to study antigen presenting cell (APC) maturation as well as for studies of growth and tumorigenicity of acute myelogenous leukemia.