This gene encodes a member of the plasticity-related gene (PRG) family. Members of the PRG family mediate lipid phosphate phosphatase activity in neurons and are known to be involved in neuronal plasticity. The protein encoded by this gene does not perform its function through enzymatic phospholipid degradation. This gene is strongly expressed in brain. It shows dynamic expression regulation during brain development and neuronal excitation. Alternatively spliced transcript variants encoding the same protein have been observed. Possesses similar cytotoxic and cytostimulatory activities to PRG2/MBP. In vitro, stimulates neutrophil superoxide production and IL8 release, and histamine and leukotriene C4 release from basophils.