IRAK4, also known as Interleukin-1 receptor-associated kinase 4, is a serine/threonine-protein kinase that plays a critical role in initiating innate and adaptive immune responses against foreign pathogens. It activates NF-kappaB in both Toll-like receptor (TLR) and T-cell receptor (TCR) signaling pathways.
RANKL is the ligand for the receptor activator of NFkB (RANK) that belongs to the tumor necrosis factor receptor (TNFR) superfamily. RANK overexpression induces the NFkB and c-Jun-terminal kinase (JNK) downstream pathways. This pathway has been studied in detail in the bone remodeling system with regards to osteoclast activity and induction.
MyD88, also called myeloid differentiation primary response gene 88, encodes a cytosolic adapter protein that plays an essential role in innate and adaptive immune responses. The innate immune system recognizes the presence of bacterial pathogens through the expression of a family known as Toll-like receptors (TLRs).
Toll-like receptors (TLRs) play an essential role in the activation of innate immunity, and TLRs are expressed in a large number of immune cells like B-lymphocytes, monocytes, plasmacytoid dendritic cells and at low levels in human respiratory cells as well as in epithelial cells.