Paul Ehrlich (14 March 1854 – 20 August 1915) was a German scientist in the fields of hematology, immunology, and chemotherapy, and Nobel laureate. He is noted for his research in autoimmunity, calling it "horror autotoxicus". He coined the term "chemotherapy" and popularized the concept of a "magic bullet".
Paul Ehrlich was born into a Jewish family in Strehlen, in the German Kingdom of Prussia, Province of Silesia, (now in Poland). As a schoolboy and student of medicine he was interested in staining microscopic tissue substances.
In his dissertation at the University of Leipzig, he picked up the topic again ("Contributions to the Theory and Practice of Histological Staining", Beiträge zur Theorie und Praxis der histologischen Färbung). He married Hedwig Pinkus (then aged 19) in 1883. The couple had two daughters, named Stephanie and Marianne. After his clinical education and habilitation ("The Need of the Organism for Oxygen ", Das Sauerstoffbedürfnis des Organismus) at the Charité in Berlin in 1886 he received a call from Robert Koch to join the Institute for Infectious Diseases in Berlin (1891).