I don’t need to tell you that we live in a very uncertain world. This reality is all around us, screaming at us from our TV sets or computer screens. If it’s not the pandemic, wars, or natural disasters, then it’s the galloping inflation or energy...

I followed the lab worker through a metal door that opened into a barely lit cement room. After I crawled onto a rusty exam table, I purposely took a slow breath. That breath was a bit jagged but it steadied my pounding heart. I’d donated pints of...