Heme-induced TLR4 activation in endothelial cells leads to NF-κB activation, adhesion molecules expression and Weibel–Palade body degranulation (Belcher et al., 2014), which contains the VWF and P-selectins, molecules involved in SCD vasculopathy (Matsui et al., 2001; Chen et al., 2011a; Figure 4). The gene discussed is TLR4; the disease is Schnyder corneal dystrophy.