A number of mechanisms have been identified that may contribute to the observed association between both conventional chemotherapies (blue boxes) or targeted therapies (grey boxes) and an increased risk of thrombotic events. CDK, cyclin dependent kinase; EGFR, epidermal growth factor receptor, RTKI, receptor tyrosine kinase inhibitor; VEGF, vascular endothelial growth factor; VEGFR, vascular endothelial growth factor receptor.