Long story.
My dad was diagnosed with T2D, then a few years later my mom with Alzheimer's. I decided I needed to really understand, started digging through journals, learning the biochemistry as needed. I got fascinated, particularly with all the new stuff being discovered - reminds me of when I got involved with microprocessors, everything so new.
So, DNA of course (just 23&me, not the complete workup that's a couple of grand). Then promethase and digging through SNPs.
So, yeah - my own research. If you look at some of my responses, you'll see I'm using the Feinman method (teach other people) to get stuff straight in my own head.