Inhibition of ALK1 signal transduction using a truncated form of the receptor coupled to an Fc-domain led to decreased angiogenesis in diverse in vitro models (e.g., in a spheroid sprouting assay using endothelial cells, HUVEC) as well as decreased tumor development in the RIP1-Tag2 mouse model [96]. This evidence concerns the gene ACVRL1 and neoplasm.