| METHODS : The authors analyzed the correlation among expression of Dab 2 , presence of basement membrane ( collagen 4 and laminin ) , morphologic alteration of the surface epithelial cells , and expression of the mitotic index marker Mib 1 in 50 archived ovarian tumors by an immunohistochemical approach . ^^^ The stainings of Dab 2 , Mib 1 , collagen 4 , and laminin in premalignant lesions bordering both normal and neoplastic ovarian surface epithelium from adjacent slides were analyzed in 50 ovarian tumors . ^^^ RESULTS : In these 50 ovarian tumors , the percentage of Mib 1 positive tumor cells distributed in a wide range , from 1 % to 75 % , and there has no strong correlation with the expression of Dab 2 . ^^^ However , in the premalignant regions bordering tumor and normal ovarian surface epithelium , the loss of Dab 2 expression closely correlated with the dysplastic morphologic transition and Mib 1 expression of the ovarian surface epithelial cells . ^^^ |