Effect of NFκB inhibition on tumour cell contact mediated endothelial cell OPG production. HuDMECs were co-cultured with the T47D cell line at HuDMEC: T47D ratios of 2:1, 4:1 and 10:1 for 72 hours in the presence or absence of the NFκB inhibitor PDTC as described in materials and methods. HuDMECs were separated from the T47D cell line and gene expression measured in the separate populations. OPG secretion was assessed using ELISA (a) and gene expression measured using real-time quantitative PCR (b). For real-time quantitative PCR, values were normalised to GAPDH and are given as fold expression compared to untreated HuDMECs. Data are represented as mean ± S.E.M. from three independent experiments. ***, p < 0.001 compared to HuDMEC: T47D 2:1 ratio co-culture without PDTC.