Tumor cells produce hormones and growth factors such as parathyroid hormone-related peptides (PTHrP), receptor activator of nuclear factor kappa B (NFκB) ligand (RANKL), granulocyte-macrophage colony stimulatory factor (GMCSF), IL-1, IL-6, and MIP-1α, which activate various bone cells such as osteoblasts and osteoclasts and disrupt the homeostatic balance in cancers such as breast and prostate cancer. This evidence concerns the gene IL1B and neoplasm.