MicroRNA-494 expression was upregulated during IDD progression; its overexpression increased the expression of ECM catabolic factors such as matrix metalloproteinase and A disintegrin and metalloproteinase with thrombospondin motif in NP cells while decreasing that of anabolic genes such as type II collagen and aggrecan; it also induced the apoptosis of NP cells, as determined by flow cytometry. Here, ACAN is linked to intervertebral disk degenerative disorder.