When I was working as a cell biologist, we would use phorbol esters as
tumor promoters. I gather that the phorbol esters were originally
isolated from croton oil, pressed from the seeds of croton tiglium. Can
anyone tell me more about these? I have occasionally seen the latter
offered for sale - they are attractive plants with copper and gold
dagger-shaped leaves. How dangerous are they? Do the leaves or sap of
the plant have tumor promoter activity as well?