ABO式血液型
In the early twentieth century, the ABO blood group system was discovered by Austrian scientist Karl Landsteiner, and its application in World War I led to a rise in the awareness of therapeutic blood donation. In Italy, there were few hospitals that could provide blood transfusions, and those that did held lists of suppliers; this closed market allowed a high price (up to several months' wages) to be charged to patients for a single unit of blood.