Adenovirus-cre was either injected into the adipose tissue surrounding the ovary (gonadal fat pad) or surrounding the testes resulting in either deletion of exons 2–10 in p53flox/flox mice,18 or exon 5 in the Ptenflox/flox mice.19 Injection of adenovirus-cre into adipose tissue of either p53flox/flox, Pten+/+ mice or p53+/+, Ptenflox/flox mice led to no tumor formation, whereas injection of p53flox/flox, Ptenflox/flox mice led to >85% of mice with tumor formation (Figure 1). This evidence concerns the gene PTEN and neoplasm.