Table 1.

Pathologic diagnosis in mice treated with BBN.

Period	Pathologic diagnosis of BBN-treated mice
1 (Weeks 4–8)	Atypia (n = 4/4)
2 (Weeks 12–16)	Squamous metaplasia (n = 3/4) Focal CIS (n = 1/4)
3 (Weeks 20–23)	Invasive carcinoma (n = 5/5)

There were two mice in each group (except for week 23, which had five). Diagnosis represents most significant findings.