POU5F1 and cancer: Similar increased OCT-4 expression is reported in various human uteropathies including endometriosis and cancer (Table 1) suggesting crucial role of VSELs/EnSCs in human endometrium and their dysregulation possibly initiates various pathologies. Human  endometrial VSELs will be small-sized cells which can be studied by flow cytometry with surface phenotype of LIN-CD45-CD133+ and will express OCT-4 and SSEA-4, besides other markers.