Overexpression of Lu/BCAM and ICAM-4 has been demonstrated in SCA (El Nemer et al., 1998, Parsons et al., 1999) and, importantly, functional activation by phosphorylation (Gauthier et al., 2005) results in increased RBC adhesion to vascular endothelium and resistance to high shear-stress forces, thereby contributing to VOC genesis (Kaul et al., 2006). The gene discussed is ICAM4; the disease is autosomal dominant cerebellar ataxia.