Table 1.

MMTV/CrkII tumor incidence

Tumor pathology	Latency (days)	Status
Adenosquamous carcinoma	327	Multiparous
Fibroadenoma-like lesion	466	Nulliparous
Glandular carcinoma	507	Multiparous
Secretory glandular carcinoma	452	Multiparous
Radial scar	449	Nulliparous
Unknown	471	Nulliparous

Mice from two MMTV/CrkII transgenic lines were divided into two groups—nulliparous or multiparous—and monitored for tumor development. MMTV/CrkII mice show a combined rate of tumor incidence of 17.6% (6/34), whereas age-matched FVB developed tumors with an incidence of 4% (1/25).