The pathogenic mechanisms of a disease (or condition) are set in motion by underlying etiological causes, which if controlled would allow the disease to be prevented. Often, a potential etiology is identified by epidemiological observations before a pathological link can be drawn between the cause and the disease. The pathological perspective can be directly integrated into an epidemiological approach in the interdisciplinary field of molecular pathological epidemiology (MPE). MPE can help to assess pathogenesis and causality by means of linking a potential etiologic factor to molecular pathologic signatures of a disease.