Scientists claim to have identified a master gene which is able to transform blood stem cells into disease-fighting immune cells. The hope is that this discovery will allow for new treatments for cancer. "The researchers have 'knocked out' the gene in question, known as E4bp4, in a mouse model, creating the world's first animal model entirely lacking NK cells, but with all other blood cells and immune cells intact. This breakthrough model should help solve the mystery of the role that Natural Killer cells play in autoimmune diseases, such as diabetes and multiple sclerosis. Some scientists think that these diseases are caused by malfunctioning NK cells that turn on the body and attack healthy cells, causing disease instead of fighting it. Clarifying NK cells' role could lead to new ways of treating these conditions."