It represents a huge achievement, and the culmination of a long team effort.

A pregnant woman’s blood sample taken in 1972 was mysteriously missing a surface molecule found on all other known red blood cells at the time.

More than 50 years later, that strange absence finally led researchers from the UK and Israel to describe a new blood group system in humans. The team published a paper on the discovery in 2024.

“It represents a huge achievement, and the culmination of a long team effort, to finally establish this new blood group system and be able to offer the best care to rare, but important, patients,” hematologist Louise Tilley from the UK National Health Service said in September 2024, after nearly 2 decades of personally researching this bloody quirk.