MMP1 and cancer: Additional factors secreted by cancer cells, such as hypoxia-induced lysyl oxidase (LOX), colony stimulating factor 1 (CSF-1), tumor necrosis factor α (TNFα), vascular cell adhesion molecule 1 (VCAM-1), matrix metalloproteinase 1 (MMP1), Jagged 1, and interleukins 8 and 11, also induce the activation of osteoclasts, some of them directly, independently of RANK, enhancing the imbalance [27,32,39,40,41].