Researchers from the UK and Israel have identified a new blood group system in humans, marking a major breakthrough in hematology.

The discovery, published in September, stems from a puzzling case in 1972, solving a half-century-old mystery and deepening our understanding of human blood diversity.

The case involved a pregnant woman whose blood lacked a surface molecule found on nearly all human red blood cells.

This molecule, now identified as the AnWj antigen, eventually led to the classification of the MAL blood group system after decades of dedicated research. "It represents a huge achievement, and the culmination of a long team effort," says Dr Louise Tilley, a hematologist at the UK National Health Service who has spent nearly 20 years studying this rare blood variation. "This discovery enables us to provide the best care to rare, but important, patients." According to the World Health Organisation's global blood safety database, understanding blood group variations is essential for ensuring safe transfusions.