Macrophage Term Analysis

Our relationship with iron is much more complex than it’s been considered traditionally. It’s essential—but it also provides a proverbial leg up to just about every biological threat to our lives. […] Parasites hunt us for our iron; cancer cells thrive on our iron. Finding, controlling, and using iron is the game of life. For bacteria, fungi, and protozoa, human blood and tissue are an iron gold mine. Add too much iron to the human system and you may just be loading up the buffet table.

Then, in 1347, the plague begins its march across Europe. People who have the hemochromatosis mutation are especially resistant to infection because of their iron-starved macrophages. So, though it will kill them decades later, they are much more likely than people without hemochromatosis to survive the plague, reproduce, and pass the mutation on to their children. In a population where most people don’t survive until middle age, a genetic trait that will kill you when you get there but increases your chance of arriving is—well, something to ask for.