Pan-cancer analysis of the prognostic and immunological role of matrix metalloproteinase 9

Abstract Matrix metalloproteinase 9 (MMP9), a zinc ion-dependent endopeptidase, is one of the most complex matrix metalloproteinases in the gelatinase family. During tissue remodeling, MMP9 leads to gelatin and collagen degradation, which in turn promotes tumor invasion and metastasis. However, comprehensive pan-cancer analysis has not been performed for MMP9. In addition, the diagnostic and prognostic value of MMP9 as a cancer biomarker remain poorly understood, as well as the utility of MMP9 expression as a predictor of immunological responses. Based