IL20 and intervertebral disk degenerative disorder: The abnormal stress in lumbar disc level may cause the production of minor fissures, which then induce immune or inflammatory reaction and increase the contents of inflammatory factors in annulus fibrosus.3-5 As IL-20 is an arteriogenic cytokine12, in the process of disc degeneration, IL-20 may promote the vascular growth into the fissure of annulus, promote the degradation of matrix, affect the synthesis of proteoglycan and aggravate the degeneration of intervertebral disc.