IM subspecialties that could be useful for Doctors Without Borders?

Applied IM this year. One of my goals is to be able to join DWB and serve at least part of my year overseas. Have been planning on eventually applying to GI for a while now, but I honestly worry about the utility of GI in under resourced countries.

What subspecialties would be the most useful to have in these missions? I would think ID for sure - maybe crit care? Interventional cards?