MMP9 and neoplasm: Network analysis using STRING v9.1, comprised of functional protein interactions, uncovered a high-scoring protein network in ascites relevant for intraperitoneal tumor spread, consisting of genes involved in EMT, epithelial cell characteristics, and steroid-thyroid hormone-retinoid receptor activity, as well as NFKBIA, IL8, TGFB1, ERBB2, MMP9, and MMP12 as hub-genes (Figure 3).