Pre- and postoperative CRP serum levels and WBC count in 347 patients were retrospectively assessed after complication-free, single-level open posterior lumbar interlaminar fusion (PLIF) (n = 150) for disc degeneration and spinal stenosis and endoscopically assisted lumbar discectomy (n = 197) for herniated lumbar disc. The gene discussed is CRP; the disease is spinal stenosis.