MMP9 and cancer: A study by Halberg et al. (2016) has shown PITPNC1 to be frequently amplified (across 2% of cancers) and responsible for the secretion of matrix metalloprotease 9 (MMP9), platelet-derived growth factor (PDGF) and HTRA1 (a serine protease involved in epithelial-to-mesenchymal transition) in malignant tumors.