TRA-1-81

TRA-1-81 (Podocalyxin); TRA-1-81; Podocalyxin; Keratan Sulfate; KS

TRA-1-81 is a cell surface antigen expressed along with SSEA-3, SSEA-4 and TRA-1-60 in human embryonic stem cells, embryonal carcinoma cells and induced pluripotent stem cells (iPS). These surface markers are down-regulated during the differentiation process. In contrast, SSEA-1 is absent in undifferentiated human stem cells but is present on the cell surface after retinoic acid mediated differentiation.