Our previous research showed restoration of spinal cord KCC2 expression after HDAC2-shRNA application in a bone cancer pain rat model (Lin et al., 2017; Hou et al., 2018) Consistent with these results, our present study showed that enhanced expression of KCC2 in the spinal cord after HDAC2 knockdown may account for the analgesic effect resulting from HDAC2 suppression. The gene discussed is HDAC2; the disease is bone neoplasm.