Karl Landsteiner, renowned scientist and medical researcher, passed away on June 26th, 1943 at the age of 75. Born in Vienna, Austria on June 14th 1868, Karl earned his medical doctorate from the University of Vienna and specialized in bacteriology and pathology. He was the first to demonstrate that the ABO blood groupings existed in humans as well as to identify the correct blood groupings and to discover the graphics that would eventually designate the ABO system. In 1914, Karl co-published a paper about the fundamentals of the Rhesus blood factor, furthering the ability of blood transfusions. For his contributions, Karl was awarded a Nobel Prize in physiology in methodology in 1930. An accomplished and widely respected scientist, Karl published nearly 300 papers throughout his career. He also served as a professor of Pathological Anatomy at the University of Vienna and Pathology Department Chairman at the University of Rome. Karl's ground-breaking contributions to medical science will be remembered and honored for years to come. He will be greatly missed.