What causes breast cancer? It may be genetic, caused by an abnormal gene. Hormones are another possible cause, and the list goes on to include diet and environmental issues. Now a new possibility has been added to the list - the common house mouse.

According to the Examining Room of Dr. Charles in the Science Blog:

Growing evidence suggests that breast cancer may be partly caused by infection with a retrovirus known as (HMTV). It is closely linked to mouse mammary tumor virus (MMTV) which causes breast cancer in mice. MMTV and HMTV are 95% genetically identical, and MMTV is known to jump species.

Mice are pests that have tormented men since the beginning of civilization. Lately they've been tagged as spreaders of disease, including the deadly hantavirus. Pest Control Canada has this to say about mice and hantavirus:

Wild mice transmit another serious disease. Hantavirus pulmonary syndrome is a rodent-borne virus that can cause severe respiratory problems and even death. Hantavirus is spread through the urine, saliva and feces of rodents, especially the deer mouse. Humans contract the disease by breathing dried particles of their urine or feces. This can occur by cleaning an indoor area that was infested by deer mice. The disease causes a victim's lungs to fill with liquid. Symptoms include muscle aches, fever and possibly chills, headaches, nausea, diarrhea, abdominal pain and coughing. The symptoms develop within one to six weeks after exposure.

And now breast cancer? It's time we made the mouse an endangered species.