Ludwik Hirszfeld (1884–1954) was one of the most distinguished scholars of his era. He was primarily engaged in blood research. He gained fame for the blood group classification system — A, B, AB, and 0 — still in use today. He co-founded the Institute of Immunology and Experimental Therapy of the Polish Academy of Sciences in Wrocław, which now bears his name. On the occasion of the 130th…