Podocalyxin (PODXL) is a CD34 family member expressed by podocytes, vascular endothelium, mesothelium, and a subset of hematopoietic progenitors. It is the major sialoprotein in the glycocalyx of glomerular podocytes. The physiological role of podocalyxin in leukemic blasts is unknown. However, it is thought of as a candidate prostate cancer tumor aggressiveness gene. Podocalyxin appears to complement CD34 as a useful cell surface marker for hemangioblasts, the common precursors of hematopoietic and endothelial cells.