passages.id: split_6_test_2426_passage
passages.type: progene_text
passages.text: Endoglin is an auxiliary component of the transforming growth factor - beta ( TGF-beta ) receptor system , able to associate with the signaling receptor types I ( TbetaRI ) and II ( TbetaRII ) in the presence of ligand and to modulate the cellular responses to TGF-beta1 .