ACVRL1 and neoplasm: Since endoglin, like ALK1, binds to BMP-9 and -10, a soluble form of this protein, coupled to an Fc-domain was used to neutralize BMP-9 in the colon-26 mouse tumor model and, similar to soluble ALK1, it reduced the tumor burden in these mice due to its anti-angiogenesis properties [34].