Researchers discovered an entirely new human blood type after solving a 50-year mystery.

Back in 1972, doctors were stumped when a pregnant woman’s blood sample was missing a surface molecule that was present on everyone else’s red blood cells at the time. No one could explain it.

Fast forward fifty years, and scientists believe to have sussed it. The discovery led researchers from the UK and Israel to describe a new blood group system in humans, publishing their findings in 2024.