Probable adipokine. Activates AMPK, AKT, and p44/42 MAPK signaling pathways. Multimers (predominantly trimers). Interacts with ADIPOQ via the C1q domain to form a heterotrimeric complex. Expressed predominantly in adipose tissue. Females express higher levels than males. The isomeric forms of the hydroxylated amino acids could not be determined in the mass-spectrometric methods reported in PubMed:18787108 but are assumed on the basis of their occurrence in collagen-like domains. Overexpression of CTRP9 in obese (ob/ob) mice significantly lowered serum glucose levels.