Scientists have successfully identified the genetic cause of the AnWj blood group antigen. With this discovery, they have solved a mystery that lasted since 1972, thus 50 years. Based on this finding, a new blood group system, named MAL, has been established. This groundbreaking revelation has the potential to significantly simplify the search for extremely rare AnWj-negative patients and donors. Simultaneously, it can protect these individuals from potentially dangerous transfusion reactions. This represents a significant advancement in medicine, improving the safety of blood transfusions for a specific group of people.