This link should help, Pauline:
I hope it helps!
Damp sponge with a bit of dish soap.
Try rubbing it with any oil-- baby oil, vegetable oil, etc. to see if this breaks the protein down. Keep rubbing. Also, try a Mr. Clean Magic Eraser or even nail polish remover. If they all fail, take the cabinet door to the home improvement store and see if they have a product that may work.