The formation of malignant tumors by cells expressing only RasG12V and p53DD was unexpected since it has been previously shown that adrenocortical cells require at least the ablation of two tumor suppressor genes (p53 and Rb through the expression of LT antigen) and the mutation of one oncogene (expression of RasG12V) to undergo transformation [24]. Here, RB1 is linked to neoplasm.