TNFRSF11B and breast cancer: Mechanistic studies in osteoblasts confirmed the role of osteoblast-specific IKKβ in the reciprocal interaction between osteoblast and breast cancer cells by showing that pre-exposure of osteoblasts to IKKβ inhibitors reduced RANKL and OPG production by osteoblasts and these effects were accompanied with significant inhibition of IκB phosphorylation.