MAPK3 and breast cancer: Chemotherapy and radiotherapy enhance bone damage and inhibit bone remodeling51 by inducing osteocyte death and osteoclastogenesis through increased production of the inflammatory cytokines IL-6 and IL-11.52 This inflammatory cytokine release is regulated by ERK1/2.53 Inhibition of ERK1/2 signaling may provide a novel strategy to reduce bone damage induced by chemotherapy and/or radiotherapy in the setting of metastatic breast cancer.