JAG1 and neoplasm: In the bone niche, tumor cells instigate osteoclastic bone resorption, leading to TGF-β release from the bone matrix, which binds to the tumor cells and stimulates the expression of osteolytic factors like Parathyroid Hormone-Related Protein (PTHrP) (Yin et al., 1999) and Jagged1 (Sethi et al., 2011).