IL6 and infection: We have read with great interest the paper published in a recent issue of ISRN Urology by Bantis et al. [1] entitled “can tumor necrosis factor-α and interleukin-6 be used as prognostic markers of infection following ureteroscopic lithotripsy?” in which they report preoperative and postoperative serum interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) levels in patients with urolithiasis.