A drug used with bevacizumab to treat certain types of hepatocellular carcinoma (a type of liver cancer). It is also used alone or with other drugs to treat adults with certain types of non-small cell lung cancer, small cell lung cancer, breast cancer, and urothelial cancer (a type of bladder cancer). It is also being studied in the treatment of other types of cancer. Atezolizumab binds to a protein called PD-L1, which is found on some cancer cells. Atezolizumab may block this protein and help the immune system kill cancer cells. It is a type of monoclonal antibody and a type of immune checkpoint inhibitor. Also called Tecentriq.