How Do I Refresh A Derma Panel?

I have items being displayed in a derma panel, these items are read from a list when the panel is opened.

My Question is, how do I refresh the Derma panel when one of the items is removed from the inventory?
I’ve tried reopening the panel, but there’s a hook that is called when the player presses F2 that sends the inventory information to the panel, so to speak.

Only send the information when you need it, then save it on the clientside. If someone spams the F2 button he can cause quite a lot of networking wasted if you have such system that you said. Never trust the client.
Send the information when it’s changed on the server, save it on the client, then just open the menu with the F2 button.

Okay, I’ll take that into account, but the problem still remains.

When someone drops an item from the inventory the item will remain in the inventory until the menu is closed and re-opened.

you can call panel:InvalidateLayout( ) I believe