99超碰中文字幕在线观看-天天干天天日天天舔婷婷-我看操逼的好看的女人的-日本一二三四五区日韩精品

CD71, also known as transferrin receptor 1 （TfR1）, is a type II transmembrane glycoprotein that exists as a disulfide-linked homodimer on the cell surface. It plays a crucial role in cellular iron uptake by binding to iron-bound transferrin and mediating its internalization through receptor-mediated endocytosis. CD71 is widely expressed on proliferating cells, including erythroid precursors, activated immune cells, and various cancer cells. It is also a preferred entry receptor for several viruses, such as arenaviruses and hepatitis C virus. In addition, CD71 has been identified as a marker for cell proliferation and activation, and its expression is often used in the diagnosis and prognosis of hematological diseases.