CLDN4 and ovarian cancer: To investigate the functional association of claudin-4 with genomic instability in ovarian cancer and to better represent the known heterogeneity of these diseases (1), we modulated claudin-4 expression in three diverse EOC cells: OVCAR3 and OVCA429 (as claudin-4 downregulation system) and OVCAR8 (as claudin-4 overexpression system) using CRISPR interference and lentiviral transduction, respectively (see Supplementary Fig. S1A).