In this recently and inexplicably locked thread WoodenTaco mentions that cilantro contains PTC and that’s the end-all be-all answer to why some people like and some people hate cilantro.
It seems like it would be relatively easy to verify if cilantro contains PTC in significant quantities, but my google-fu in this matter is weak. I have discovered that broccoli contains PTC. In fact quite a few plants contain PTC, most of which I haven’t heard described in such glowing invective as cilantro.
I’m also curious if the PTC concentration varies over the life of the plant or if there’s any accounting for leaves from the same plant sometimes tasting soapy and sometimes not.