In sickle cell disease, BCAM is abundant on erythrocytes, where it mediates the adhesion to LN‐511‐expressing endothelial cells (ECs),9, 10 and interaction of BCAM on erythroid cells with LAMA5 on ECs has also been observed in polycythemia vera.11 The gene discussed is LAMA5; the disease is sickle cell disease.