Sort:  

I think CRSPR technology has the greatest potential for eliminating/curing cancer. CRSPR is essentially a gene editing tool that allows doctors to go in and edit the human genome, snipping out unwanted genes. It is still in the trial stage and there are many tests that need to be conducted, but it has the potential to modify humans as we know it.

Without going into the scientific terms too much, it is essentially a tool that we can use to cut out or erase problematic genes before they become problematic. The use cases are endless but also raise ethical/moral questions as we might be able to select which desired traits we want in our offspring etc.

Either Cannabis or mushrooms such as reishi, corteceps, and chaga. The studies on the latter three are getting quite intriguing, even for a non medical person such as myself. I've been a lay person studying this, so an actual herbalist would have better knowledge than me, though.

Definitely cannabis lol... though I've heard it's best to consume it by eating it or using extracts, rather than plain smoking it. There was a study by a Spanish scientist that showed it limits tumor growth, then shrinks it until it disappears.