'The active ingredient in marijuana cuts tumor growth in common lung cancer in half and significantly reduces the ability of the cancer to spread, say researchers at Harvard University who tested the chemical in both lab and mouse studies.

They say this is the first set of experiments to show that the compound, Delta-tetrahydrocannabinol (THC), inhibits EGF-induced growth and migration in epidermal growth factor receptor (EGFR) expressing non-small cell lung cancer cell lines. Lung cancers that over-express EGFR are usually highly aggressive and resistant to chemotherapy.'

Read more: Marijuana Cuts Lung Cancer Tumor Growth in Half, Harvard Study Shows