CLDN4 and endometrial cancer: In addition, although the overall levels of CLDN-4 protein were lower compared with those of CLDN-3, we also observed overexpression of CLDN-4 in the EFE-184, MES-SA, MFE-296, MFE-319 and RL95-2 endometrial cancer cell lines relative to THESCs (Figure 2B).