Sequence alignment of endoglin from different species. The protein sequences of rat, mouse, human, and chicken endoglin were aligned using the ClustalW2 tool (http://www.expasy.org/genomics/sequence_alignment). Sequences of mouse (NP_031958), rat (AAS67893), human (NP_001108225) and chicken (AAT84715) were taken from the GenBank (http://www.ncbi.nlm.nih.gov/). The Arginine-Glycin-Aspartic acid sequence in human endoglin (aa 399-aa 401) is underlined. Fully conserved aa in endoglin are marked by asterisk (*), positions that carry aa with strongly similar properties by a colon (:) and positions with weakly similar properties by a period (.), respectively. Please note that the highest degree of homology is found at the C-terminal regions that encompass the cytosolic part of endoglin.