The possible role of EPO, a common hematopoietic growth factor,in the treatment on nonunion has been examined both systemically andwith local application in rabbit radii.128 Interestingly, both the locally applied EPO sponge group and thesystemic application group demonstrated increases in bone formationand callus vascularization.128 However,there are many known side effects of EPO administration, such as butnot limited to reports of seizures, hypercoagulability, and hypertension.128,141. The gene discussed is EPO; the disease is thrombophilia.