Ribonuclease Inhibitor(RI) is an acidoglycoprotein in kytoplasm that lies in the mammalian organs and tissues,in which placental tissue has the most.

• 核糖核酸酶抑制因子(RI)是一种存在于胞浆中的酸性糖蛋白,它广泛存在于哺乳动物的组织器官中,以人胎盘组织中含量最丰富。