CLDN3 and ovarian cancer: The same CPE toxin selectivity towards claudin-3/-4 was further studied by the authors of [39], who have characterized poly(lactic-co-glycolic-acid) (PLGA) NPs modified to bear a COOH-terminal domain binding CPE for the delivery of DT-A to chemotherapy-resistant ovarian cancer cells, under the transcriptional control of an ovarian specific p16 promoter, which is highly differentially expressed in ovarian cancer cells.