“Tumoricidal or tumorigenic actions of NO [nitric oxide] are highly dependent on the conditions in the tumor microenvironment. A number of experimental and clinical examples confirm the duality of the cellular effects of NO and the significance of other factors independent of NO that may ultimately determine its biological role at any given time.”

According to the same source …

“The role of NO and estrogens in breast cancer is still unclear, although the balance tends to lean toward a procarcinogenic action. In combination with a NO donor agent, a cathecol-estrogen was shown to synergistically induce DNA strand breakage. The DNA damage was much more pronounced than the one produced by each substance alone. These effects were inhibited by NO-trapping agents and by antioxidants. Both NO and cathecol-estrogen are formed in the human breast and uterine tissues, and their synergism generates potent ROS [reactive oxygen species] that may be involved in hormone-induced carcinogenesis. Similarly, cNOS [constitutive nitric oxide synthase] has been shown to be present in various human tumor cell lines such as neuroblastoma, cervix carcinoma, and breast cancer cells, where it correlates strongly with the expression of estrogen receptor.”

“An incandescent bulb has a color temperature of 2400K, which means it contains far less blue and far more yellow and red wavelengths. Before electric light, we burned wood and candles at night; this artificial light has a CT of about 1800K, quite yellow/red and almost no blue. What we have now is very different.”

http://www.cnn.com/2016/06/21/health/led-streetlights-ama/