RELB and breast cancer: Therefore, we assessed the relative expression of IKBKB, p50, p65, NIK, RELB, IL-8, and MMP-1 using quantitative real-time PCR (qPCR) in seven breast cancer cell lines classified according to their molecular subtype: Luminal, MCF-7 and T47D; Her2, BT474 and SKBR3, and Basal, MDA-MB-453, MDA-MB-468 and MDA-MB-231 53, and the inflammatory breast cancer (IBC) cell line SUM149.