ABSTRACT
When studying the toxicity of drugs and other chemicals in humans and other animals, it is necessary to use biological markers or biomarkers. There are three reasons for this; firstly, the study of toxicity requires a knowledge of the dose or level of the substance to which the animals or patient is exposed. Secondly, the study of toxicity also requires a means of detecting and quantifying the pathological effect. Finally, the study of the toxicity may require an understanding of the factors which affect the occurrence of the pathological response.
