MMP9 and neoplasm: As stated by a literature review by Palmini and Brandi [47], many recent studies evaluated the role of micro-RNAs in the pathogenesis of GCTB, describing how some miRNAs can act as tumor suppressors or oncogenes, targeting various genes, such as homeobox A1 (HOXA1), tartrate-resistant acid phosphatase (TRAP), cathepsin K (CK), matrix metallopeptidase 9 (MMP-9), cytochrome C oxidase assembly factor 1 homolog (COA1), protein disulfide isomerase family A member 6 (PDIA6) genes and even the Akt signaling pathway.