MCF10A and H-Ras MCF10A cells were established and cultured as previously described.35 (link) Hs578T cells were purchased from the Korean Cell Line Bank (Seoul, Korea) and MCF-7 cells were from American Type Culture Collection (Manassas). MDA-MB-231 cells were kindly provided by Dr. Dong Young Noh (Seoul National University, Seoul, Korea). MDA-MB-231, Hs578T, and MCF7 cells were cultured as described.36 (link) Cell lines were authenticated by the Korean Cell Line Bank using STR-PCR analysis.