 These cells are derived from the mesoderm during embryonic development and are closely related to the mesothelium of the peritoneum.The germinal epithelium gives the ovary a dull gray color as compared with the shining smoothness of the peritoneum; and the transition between the mesothelium of the peritoneum and the cuboidal cells which cover the ovary is usually marked by a line around the anterior border of the ovary.Ovarian surface epithelium can give rise to surface epithelial-stromal tumor.