Toxicology is the study of toxin effects on human health toxin effects on the environment risks and hazards the relationship between toxin exposure and disease development the relationship between chemical exposure and disease development

Toxicology is the study of toxin effects on human health. The individuals or professionals who carry out toxicology are called toxicologists. In toxicity testing, the dose of a chemical above which there is a measurable decline in the health of the organism being tested is referred to as the toxicity threshold. After identifying the effects and the toxins in the body of an organisms toxicologists device ways of removing or neutralizing the toxin so as to avoid any damaging effects to the body tissues. 

Icant be totally sure but i would say with confidence that it is example #1 about cells.