Appelboom et al. (2013) found that VWF rs216321 polymorphism was significantly associated with relative hematoma growth and approached a borderline association with absolute hematoma growth. It has been reported that the rs216321 variant could decrease the ability of vWF to activate platelets and enhance the ability of vWF to carry factor VIII (Vaidya et al., 2010). Furthermore, combined exposure to hypertension and low levels of vWF largely increased the risk of ICH compared with their separate effects (Johansson et al., 2004), indicating a possible synergistic interaction between them. The gene discussed is VWF; the disease is hematoma.