MMP9 and cancer: Furthermore, it can be seen from Figure 6C, by the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, several key signaling pathways, such as transcriptional misregulation in cancer pathway [CXCL8, CD14, cyclin-dependent kinase inhibitor 1A (CDKN1A), ITGAM (CD11b), ID2, BCL6, ITGB7, MMP9, CEBPB, ERG, and TFE3 were enriched), cytokine–cytokine receptor interaction pathway (CXCL8, IL10, IL1R1, IL1B, INHBB, CCR2, IL17RB, CXCL16, CCL2, TNFSF9, BMP2, and CSF2RA were enriched), which were associated with the differentiation of NB4 cells.