May regulate the number of excitatory synapses that are formed on hippocampus neurons. Has no effect on inhibitory synapses. Interacts with ADGRB3 (PubMed:21262840). Forms heterooligomers with C1QL4, when proteins are coexpressed; this interaction does not occur after secretion (PubMed:23449976). Expressed in brainstem. More abundant in areas of the nervous system involved in motor function, such as the Purkinje cells of the cerebellum, the accessory olivary nucleus, the pons and the red nucleus.