RANKL (also known as
TRANCE or OPGL) is a member of the TNF ligand superfamily. RANKL is produced by
T cells, mammary epithelial cells and endothelial cells. RANKL, through its ability to stimulate
osteoclast formation and activity, is a critical mediator of bone resorption
and overall bone density. RANK and RANKL are key regulators of bone remodeling
and regulate T cell/dendritic cell communications, and lymph node formation.RANK-RANKL
signaling not only activates a variety of downstream signaling pathways
required for osteoclast development, but crosstalk with other signaling
pathways also fine-tunes bone homeostasis both in normal physiology and
disease.