AKT1 and neoplasm: On the other hand, miR-21 by decreasing PTEN, which is one of its tumor suppressor’s targets, upregulates the activity of two signaling pathways, the phosphatidylinositol 3-kinase/ protein kinase B (PI3K/AKT) and the mitogen-activated protein kinase/ extracellular signal-regulated kinase (MAPK/ERK) pathways, contributing to increased cell survival and drug resistance [201].