Procarcinogen definitions

procarcinogen

Substance that has to be metabolized before it becomes a carcinogen. [2]
Found on http://sis.nlm.nih.gov/enviro/iupacglossary/glossaryp.html

---

procarcinogen

(pro″kahr-sin´ә-jәn) a chemical substance that becomes a carcinogen only after it is altered by metabolic processes.
Found on http://www.encyclo.co.uk/local/21001

---