However, the expression levels of cyclin D1 and c-myc, but not those of Bcl-2 and Mcl-1, were increased upon PIAS3 overexpression in MCF7 cells, suggesting that the PIAS3-mediated effects on ER-positive breast cancer cells may be promoter-specific or ER-related. This evidence concerns the gene CCND1 and breast carcinoma.