Studies support the theory that there are several causes, instead of a single environmental cause or genetic problem.

VOA: special.2009.01.06

A separate study found no support for a theory that a biomarker called C-reactive protein causes heart disease.

VOA: special.2009.07.15

This would support a theory that the fish became poisoned in coastal waters before entering the harbor.

VOA: special.2011.03.15