ZIOP/XON Form Solid Partnerships With Merck KgaA & NCI CAR-T Superstar Rosenberg for Solid Tumors â ZIOPâs partner Intrexon (XON) has delivered two more exciting partnerships that ZIOP receives 50% of all assets and economics. The fact that the deals were both primarily announced by XON has caused a bit of confusion. For example, …