What do you mean by "what if"? I'm pretty sure human bodies have tons of random errors all the time. Personally, my left biceps occasionally twitches just enough for it to be really annoying. Then there's also that time when your body finds out it's time to make a gigantic zit on the tip of your nose even though you were through puberty 8 years ago. And suddenly, a cell decides it's time to multiply like crazy and become huge lump.