Apple - What is the keyboard shortcut for editing a cell in Excel?

Office for Windows: F2
Office for Mac: Ctrl + U

The problem is that the shortcut has been changed for earlier versions of excel.

F2 used to work on Excel versions before 2011. For the 2011 excel version use ctrl + U instead.

I believe F2 still works, its just that on macs now, to get F2, you need to press fn+F2, otherwise it does the alternative function, which in my mac is to brighten the screen.