Mouse CD254 (RANK Ligand) Recombinant Protein. Receptor Activator of NF-kB Ligand (RANK Ligand) is a cell-bound marker (CD254) related to the TNF family of proteins. RANK Ligand plays a critical role in bone metabolism, particularly osteoclast differentiation. In addition, RANK Ligand is expressed by some T cells is thought to promote dendritic cell maturation.