AKT1 and intervertebral disk degenerative disorder: The pathophysiological process of IDD is regulated by multiple intracellular signaling pathways, including the common nuclear factor kappa B (NF-κB), mammalian target of rapamycin (mTOR), phosphoinositide 3-kinase/protein kinase B (PI3K/AKT), AMP-activated protein kinase (AMPK), and mitogen-activated protein kinase (MAPK) signaling pathways [40,64,65,66,67].