RIPK2 is a member of the receptor-interacting protein (RIP) family of serine/ threonine protein kinases.Association of RIP2 with the tumor necrosis factor receptor (TNFR) causes activation of NF-κB and induction of apoptosis. RIPK2 functions as a key signaling protein in host defense responses induced by activation of the cytosolic pattern recognition receptors (PRR) NOD1 and NOD2.