Using cell culture and xenograft mouse models, Kim et al., (2018a) found that ARP significantly restricted the migratory capacity of U251 glioma cells, and the effect was associated with the regulation of matrix metalloproteinase-9 (MMP-9), a member of the zinc-metalloproteinase family involved in the degradation of extracellular matrix and pathological processes such as metastasis. The gene discussed is MMP9; the disease is central nervous system cancer.