MMP9 and myeloid sarcoma: However, only Liuzzi et al. [31] studied the effect of an olive oil extract on the concentration of matrix metalloproteinase (MMP) 9 (MMP-9; gelatinase B) and MMP-2 (gelatinase A; matrix metallopeptidase 2) in rat astrocytes stimulated with LPS and in serum samples from MS patients, suggesting that olive oil might be useful in inhibiting MMP activity implicated in the course of the inflammatory responses observed in MS.