[Ol' Dan Tucker]

The interesting thing about coal tar and psoriasis is that people with psoriasis are missing and enzyme in their skin that makes the coal tar carninogenic.

Are you saying that the the fact that they are missing the enzyme makes coal tar carcinogenic to them, or that it the enzyme itself that makes coal tar carcinogenic?

[dangerdoc]

It is an enzyme that makes the coal tar a carcinogen. Polycyclic aromatic hydratase or something similar to that, PAH for short. Coal tar treatment for people with psoriasis does not appear to increase their risk of skin cancer.

I’ll have to look it up and refresh my memory later.