CLDN1 and ovarian carcinoma: Previous studies showed contradicting impacts of miR-155 on CLDN1 expression in different disease states, where on the one hand, overexpression of miR-155 upregulated CLDN1 expression in colorectal cancer (Zhang et al., 2013), while on the other hand, repressed expression of miR-155 was correlated with CLDN1 overexpression, in ovarian cancer-initiating cells.