But it does at least seem likely that medical research would follow the money.
It will always follow the money. We cannot work for free, at least, not for very long.
There are three major funding sources.
the gov't
the charities
Pharma.
The gov't actually does a pretty good job spreading around the money. They're under a mandate to play a defensive game if there is some type of socialized healthcare system, but that makes sense.
Charities are based on popularity for a variety of reasons. Basically, you need to get people worried in between their first kids and before they have grandkids. It's why schizophrenia is so unfunded, you miss the windows, because you were too old when it strikes and too useless for anyone to really think "oh! that could happen to my kids!". Along these lines, leukemia is viewed as a childhood disease and gets pretty good funding. Breast and prostate cancer get funded reasonably well. Colorectal Cancer? Not so much. Ewy, just like those depressed people.
Once people have loved ones with any disease, they tend to start fundraising. Fundraising generates the most dollars per manhour invested. Just asking people for money (to give) goes a long way.
Pharma only gets involved if they predict they can make money. Fair enough, but they look at disease incidence/prevalence and how much money the patients can afford. And, they tend to wait until a ton of legwork has already been done.