Our DNA is over 99% identical, but why would only 38% of us get cancer?

our genes some genes are more prone to cancer then others

(I'm pretty sure)

Cancer occurs during mitosis as a result of a mutation in the genes. The thing is, not everyone's genes mutate the same way therefore not everyone will have cancer. Also, mutations are completely random and one mutation will not be enough to cause cancer. This is why although our DNA is identical, not everyone has cancer or has the same type of cancer.

a motor homunculus represents a map of brain areas dedicated to motor processing for different anatomical divisions of the body.

homunculus represents the importance of various parts of your body as seen by your brain. as a result, they take up a lot of brain space. although the cortical homunculus is a curiosity, penfield's work in mapping the brain's relationship to the body was invaluable.