tamoxifen caused a dramatic regression of tumors in animals with either high nighttime levels of melatonin during complete darkness or those receiving melatonin supplementation during dim light at night exposure.
And cancer is not sensitive to tamoxifen but rather to estrogen (which tamoxifen is an antagonist)
http://en.wikipedia.org/wiki/Tamoxifen
tamoxifen caused a dramatic regression of tumors in animals with either high nighttime levels of melatonin during complete darkness or those receiving melatonin supplementation during dim light at night exposure.