Experimental design principles for animal studies in pharmaceutical development; interval estimation with small samples for Median Lethal Dose (LD50) or Median Effective Dose (ED50); principles in statistical testing in randomized toxicological studies; subacute toxicity studies - proof of safety versus proof of hazard; design of long-term carcinogenicity studies; analysis of long-term carcinogenicity studies; design of reproductive studies; analysis of reproductive and development studies; the in vitro Ames tests; the in vitro Chinese hamster ovary cell mutagenesis studies.