MMP9 and cancer: Four pathways—insulin-like growth factor-2 mRNA-binding proteins, degradation of the extracellular matrix, activation of anterior homeobox (HOX) genes in hindbrain development during early embryogenesis, and transcriptional misregulation in cancer—are closely related to cancer pathogenesis, progression, and malignant differentiation.[21–23] Ten hub mRNAs (IGF2BP1, IGF2BP3, CAPN6, MMP9, MMP1, HOXB3, HOXB4, HOXA1, HMGA2, and WT1) are enriched in these 4 pathways (Fig. 5C).