TABLE 2.

Tumor induction by RCAS viruses encoding PyMT phosphorylation site mutants^a

RCAS virus(es)	p53 heterozygote		p53 null
	Tumor	Metastasis	Tumor	Metastasis
PyMTb	14/38	1/14	18/43	6/16
PyMT Y250A	0/32	N/A	0/17	N/A
PyMT Y315A, -Y322A	2/24	0/2	6/26	0/6

^aIncidence of grossly visible tumors, detected after sacrifice at 4 months of age or after the detection of lymphomas or sarcomas, in albumin-tv-a p53^−/− mice injected with indicated viruses. N/A, not applicable.

^bData for RCAS-PyMT are taken from Table 1.