MMP21 and cancer: In the discovery cohort, putatively pathogenic somatic mutations in orthologs of human cancer genes were present in a single tumor each including ATF6, EPAS1, FAT2, FAT4, FOXA3, FOXO1, GAB2, HRAS, KIT, KRAS, MMP21, NRAS, PBX1, and XPO1 (S3 Table).