Question: Is there a chance that there's an organ in our bodies that we don't yet know about?

Pattie Mathieu answered on 26 Feb 2018:

We have a good idea of all the things that exist in our bodies now, but it’s possible that there might be something that can do something we don’t know about yet. Recently it was in the news that we discovered a new organ in the body, the mesentery. We already knew it existed, but it wasn’t until recently that we knew it acted like an organ.