AlQa'dah 5, 1432, Oct 3, 2011, SPA - Three scientists were awarded the 2011 Nobel Prize for Medicine Monday for pioneering discoveries that has "revolutionized" the understanding of the human immune system. Bruce A Beutler of the United States and Luxembourg-born Jules A Hoffmann were cited by the Nobel Assembly in Stockholm for discoveries concerning the activation of innate immunity, the first step in the body's immune system. Canadian-born Ralf M Steinman was cited for his "discovery of the dendritic cell and its role in adaptive immunity," the Nobel Assembly said in a statement that noted his discovery of a new cell type in 1973. Their findings "opened up new avenues" for developing vaccines and therapies "against infections, cancer and inflammatory diseases," the Assembly was quoted as saying by the German Press Agency "DPA". Beutler and Hoffmann will share half the 10-million-kronor (1.4 million dollars) prize, while Steinman has been awarded other half.