Necrosis (from the Greek νεκρός, "dead", νέκρωσις, "death, the stage of dying, the act of killing") is the premature death of cells and living tissue. Necrosis is caused by factors external to the cell or tissue, such as infection, toxins, or trauma. This is in contrast to apoptosis, which is a naturally occurring cause of cellular death. While apoptosis often provides beneficial effects to the organism, necrosis is almost always detrimental and can be fatal. Cells that die due to necrosis do not usually send the same chemical signals to the immune system that cells undergoing apoptosis do...