This is my handy dandy cleaner. Sol-U-Mel. It will get anything off of anything. Seriously.
Pen marks on the wall. See the raised textured area. See that big scribble.
The stuff is a little pricey, around $10 for a little bottle. However, it is non-toxic*, all natural, and actually works.
*My kids could swallow the whole bottle and not get sick. This is important when you have a tot running a muck.