MMP9 and cancer: Six of these validated genes (BIRC5, MK167, MMP9, PLOD2, and TOP2A) have previously been implicated ccRCC,21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34 while the others have been implicated in other cancers.35, 36, 37, 38