Table 1.

Mammary tumor incidence in WapInt6sh female transgenic mice compared with wild-type female FVB/N mice at 24 months of age.

Strain and genotype	No. of mice with tumors	Total mice (N)	Tumor incidence (%)	Fisher's exact test p value	Reference
FVB/N wild-typea	0	71	0	<0.00001b	[17]
FVB/N wild-type, multiparousc	0	22	0	0.0006d	[16]
FVB/N WapInt6sh virgins	1e	26f	3.8%	0.0016g	This work
FVB/N wild-type, multiparoush	0	8	0	0.035i	This work
FVB/N WapInt6sh, multiparous	10j	24k	41.7%	NA	This work

^aReported by the National Institute for Environmental Health Sciences. For this comparison, only histological malignant lesions were scored as tumors; adenomas and other benign lesions were not included.

^bp < 0.00001 from the Fisher's exact test of previously published tumor incidence in FVB/N wild-type mice vs WapInt6sh multiparous females (row 1 vs row 5).

^cIncludes all frank tumors classified histopathologically as adenomas or adenocarcinomas.

^dp = 0.0006 from the Fisher's exact test of previously published tumor incidence in FVB/N wild-type multiparous mice vs WapInt6sh multiparous females (row 2 vs row 5).

^eHistologically, a papillary adenocarcinoma

^fTotal mice included 21 heterozygous and 5 homozygous WapInt6sh transgenic mice from J1 founder line that survived 24 months or longer.

^gp = 0.0016 from the Fisher's exact test of WapInt6sh virgins vs WapInt6sh multiparous females (row 3 vs row 5).

^hIncludes multiparous FVB/N wild-type littermates resulting from WapInt6sh heterozygous crosses. Each mouse is identified in Additional file 3.

ⁱp = 0.035 from the Fisher's exact test of wild-type multiparous vs WapInt6sh multiparous females (row 4 vs row 5).

^jOf the 11 tumors arising in 10 multiparous transgenic females, there were 4 undifferentiated tumors, 5 papillary adenocarcinomas and 2 glandular adenocarcinomas.

^kTotal mice included both heterozygous or homozygous WapInt6sh transgenic mice from J1 founder line that lived to tumor age (>12 months) and produced >1 litter.