Here, we studied the effects of the verified selective IKKβ inhibitors IKKβIII or IKKβV on osteoclast formation and osteoblast differentiation in vitro and in vivo, human and mouse breast cancer cells’ support for osteoclast formation and signalling in vitro and osteolysis ex vivo and in immunocompetent mice after supracalvarial injection of human MDA-MB-231 conditioned medium or intra-cardiac injection of syngeneic 4T1 breast cancer cells. Here, IKBKB is linked to breast cancer.