GSTM1 and renal cell carcinoma: In addition, Yang et al.21 incorrectly extracted duplicate genetic information from the studies by Wiesenhütter and Brüning, as the RCC case and control groups in Wiesenhütter et al. were comprised of case and control groups from Brüning et al. In this study, we conducted an updated meta-analysis on all currently available to validate the further relationship between the GSTM1 and GSTT1 polymorphisms and RCC.