text:  NMuMG cells treated by 11 days with 4ng/ml TGF-β, followed by TGF-β withdrawl for another 13 days, replicate 2 NMuMG (immortalized normal murine mammary gland epithelial cells) cell line: NMuMG; treatment: treated by 11 days with 4ng/ml TGF-β, followed by TGF-β withdrawl for another 13 days