Cranberries contain salvestrols and are so harvested to make the Salvestrol treatment. The sister drug of salvestrols, Abiraterone Acetate, is now offered at no charge for many residents of Canada from the government.
A pharmaceutical researcher in Leicester England named Gerry Potter researching Cytochrome enzyme pathway drugs discovered two anti cancer drugs in the early 21st century. The first, he created and works only on prostate cancer. Because it's synthetic it's eligible for patent rights. It's based on the CYP 17 variant of Cytochrome P450 enzyme family and is called Abiraterone Acetate. .
He then found by accident tangerine peel contained the CYP1B1 variant as a bitter component of the peel, and it works on all cancers, but because it's not eligible for patent not being synthetic, there is zero commercial interest in it. This is Salvestrol which in my opinion should be called vitamin F, it pretty much does to cancer what vitamin C does to scurvy. 
"An intriguing strategy for treating cancer is the design of prodrugs for specific activation by cytochromes P450 (CYPs) that are highly overexpressed in cancer cells, such as CYP1B1 (Murray et al 1997; Potter et al 2002a).In our laboratories this work has led to the discovery that the well-known dietary anticancer phytochemical, resveratrol, is metabolised by CYP1B1 in vitro cytotoxic derivatives (Potter et al 2002b). Recently we have discovered several further natural dietary phytochemicals that are specifically activated into cytotoxic metabolites by CYPs overexpressed in cancer cells. These phytochemicals comprise diverse chemical types and have been given the collective name,Salvestrols. "
Summarized here by one of the team that discovered it:
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Long (90 mins)