Not everything, only morphogenesis, which is currently unexplained either way. And it does make sense for cancer to be a morphogenesis defect, because that's essentially what it is, it's cells "forgetting" that they are part of a larger whole that has goals more important than their own ones.
Is it possible that electric potentials might play some role in some organisms? Certainly. However, we know for sure that they don't act alone. Chemical signalling definitely happens.
> And it does make sense for cancer to be a morphogenesis defect
It doesn't, really. Even assuming Levin's models are correct, most cancers have nothing to do with morphogenesis. Cancers are caused by internal genetic cell malfunctions, that stop them from reacting to external signals properly. It doesn't really matter if signals are electric or molecular ones.
The default state for normal human cells is "dead". If you take a random cell and put it in a Petri dish, it'll likely die. Most cells need to receive constant molecular signals from nearby cells to _not_ die. Once this mechanism is broken, you get cancer.
