The two parental strains which initially served as our positive and negative control showed limited effects with tamoxifen induction where the negative control did not develop tumors or mutant KRAS expression at the maximum dosage of tamoxifen (TAM) (1 mg/20 g body weight i.p. injection for five consecutive days) and the positive control developed a tumor with very low SUV with a prolonged period of latency (approx. 85–100 days) post tamoxifen administration at the highest dose. This evidence concerns the gene KRAS and neoplasm.