One of our most recent research endeavors in this area was to describe the in vitro and in vivo bio-activity of the C-terminal fragment of CPE as a potential carrier for tumor imaging agents as well as a means of intracellular drug delivery for claudin-3 and -4 positive ovarian neoplasms after i.p injection (Figure 2) [135]. Here, CLDN3 is linked to ovarian neoplasm.