An oncolytic virus is a virus that preferentially infects and kills cancer cells. However, the newly infected mosquito then infects another human. Phage therapy infects pathogenic bacteria with their own viruses. The term viral tropism refers to the cell types a virus infects. Primarily a pathogen of the mammalian respiratory system, it infects the lungs. This parasite apparently also infects the western honey bee. The virus called "Mimivirus" infects amoebae. In men, this bacterium infects the urethra. The bacterium "Micrococcus flacidifex danai" also infects larvae. EternalRocks or MicroBotMassiveNet is a computer worm that infects Microsoft Windows. Steel infects Prometheus's systems with a virus. Power Broker then infects Vries with a parasite. Influenza B almost exclusively infects humans and is less common than influenza A. It infects humans and animals and causes the disease melioidosis. PV infects and causes disease in humans alone.