Will this work on my iPhone?

I have an iPhone 4S and I was wondering if I have a screen protecter (like the sticker one) will I be allowed to have a case with a built in screen protecter like the otterbox defender or the lifeproof case without taking off my sticker screen protecter

It might reduce how well the screen will work, but I guess you can remove the plastic screen protector that comes with the case if you like.