CLDN3 and neoplasm: In this study, claudin 3 showed predominantly diffuse membrane staining in EC in contrast to a focal membrane staining pattern in the control group (2.0 [0.0;3.0]b vs 1.0 [0.0;1.0]a, respectively; P<0.005), suggesting that claudin 3 concentration is increased in tumor cell membranes compared to the normal endometrium.