In our previous study, we found that PDE2A was significantly increased in the spinal cord of chronic radiculitis rats and was dramatically inhibited by the PDE2A inhibitor, BAY 60-7550, which decreased the spinal tumor necrosis factor- (TNF-) α, interleukin- (IL-) 1β, and IL-6 levels and also alleviated radiculitis and mechanical allodynia in noncompressive lumbar disc herniation (NCLDH) rats [21]. Here, IL6 is linked to radiculitis.