MMP9 and infection: The capability of Ct to induce changes in gene expression that are consistent with EMT induction in conjunctival epithelial cells is in line with the recent finding that Ct infection can induce EMT in reproductive epithelial cells in vitro, as indicated by downregulation of the epithelial markers E-cadherin and occludin and upregulation of the mesenchymal markers SNAIL1/2, fibronectin, MMP9, T-cadherin, and ZEB1 in these cells (Igietseme et al., 2015).