Chemotherapy induced cell death series. Coloured scanning electron micrograph (SEM) of a series of cultured cancer cells (HeLa) treated with doxorubicin to cause cell death. Doxorubicin is a type of chemotherapy drug called an anthracycline. Cell death can be programmed as in apoptosis or unregulated as in necrosis From left to right are a normal Hela cell, an apoptotic cell, a necrotic cell and a dead cell lacking a cell membrane. Apoptosis (also known as programmed cell death I) is one of the main ways cancer cell death is induced by chemotherapeutic drugs. Necrosis can be a dose or time related effect of this drug in cultured cancer cells. This method of death can trigger inflammation and harm healthy cells, which is why oncolgists strive to tip the balance towards apoptosis. Magnification: x1500 when printed at 10 centimetres wide. Specimen courtesy of Greg Towers, UCL.