A study conducted by scientists at the University of New South Wales, Australia for 83 years has revealed that 40 % of breast cancer strains may be transmitted by human-to-human saliva.
The study has also linked some breast cancers to a virus linked to the domestic rat.
According to the experts, there is enough evidence that a mouse mammary tumour-like virus (MMTV) is the probable cause of many breast cancers.
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