In contrast, CCL3-/- mice treated with 4NQO presented lesions with a lower grade of cellular atypia and severity, with 57% of the lesions graded as moderate and severe dysplasia (scores of 2 and 3, respectively) (Figure 2E and 2M) and 43% classified as carcinoma in situ. This evidence concerns the gene CCL3 and in situ carcinoma.