MAPK3 and cancer: Apart from its ability to directly target EGFR mRNA, miR-7 can also target several downstream effectors of the EGFR signaling pathway, including the proto-oncogene serine/threonine protein kinase RAF-1, protein kinase B Akt, and extracellular signal-regulated kinase 1/2 (ERK1/2), sequentially inhibits cancer cell migration, invasion, and metastasis [16, 20].