How to expand another Gige?

On TX1 Board, there is a Gige, i want to expand another, how can i do that?

There is an ordinary PCIe x4 expansion slot on the development board, plus there is the M.2 Key-E slot. Additionally there are USB3 Gb adapters. Are you using the development carrier board, or some other carrier board?

Thanks a lot, we will select PCIeX4 to expand.