日韩av大片在线观看欧美成人不卡|午夜先锋看片|中国女人18毛片水多|免费xx高潮喷水|国产大片美女av|丰满老熟妇好大bbbbbbbbbbb|人妻上司四区|japanese人妻少妇乱中文|少妇做爰喷水高潮受不了|美女人妻被颜射的视频,亚洲国产精品久久艾草一,俄罗斯6一一11萝裸体自慰,午夜三级理论在线观看无码

CD34 is a highly glycosylated type I transmembrane glycoprotein that serves as a key marker for various stem and progenitor cells, particularly hematopoietic stem cells （HSCs） and hematopoietic progenitor cells （HPCs）. It is selectively expressed on the surface of early-stage HSCs, vascular endothelial cells, and some mesenchymal stem cells. Functionally, CD34 plays a crucial role in mediating cell adhesion and homing of HSCs to the bone marrow through interactions with L-selectin. It also helps maintain the undifferentiated state of progenitor cells and supports their proliferation. In clinical applications, CD34 is widely used to isolate and enrich HSCs for bone marrow transplantation and gene therapy. Additionally, its expression in certain cancers, such as leukemia and some solid tumors, makes it a potential biomarker for cancer diagnosis and a target for therapeutic interventions.