Negative regulator of NOD2 function. It down-regulates NOD2-induced processes such as activation of NF-kappa-B signaling, IL8 secretion and antibacterial response (By similarity). Involved in JNK signaling pathway (PubMed:10471813). Can form homodimers (via C-terminus). Interacts (via C-terminus) with WDR62 (via C-terminus). Interacts with MAPK9. Interacts (via N-terminus) with NOD2; the interaction is enhanced in presence of muramyl dipeptide (MDP) (By similarity). Interacts with MAPK10 (PubMed:10471813). Not detected in the cilium. Localized around the poles of the mitotic spindle from prophase to anaphase in mitotic cells. Ubiquitously expressed. Highest expression observed in brain. The N-terminal WD40 domain is necessary for the interaction with NOD2 and down-regulation of NOD2 function.