Group (a): i) Trypan blue cell viability assay for GSTM1 in HeLa cells. ii) Western blotting analysis of GSTM1 overexpression in transfected (C) and control cells (V). iii) GFP profile in transfected HeLa cells. Group (b): i) Trypan blue cell viability assay of HeLa cells transfected with GSTM2 and treated either with scrambled or GSTM1-targeted si-RNA (V-, empty vector without GSH-SF treatment, V+, empty vector with GSH-SF treatment, C-, plasmid construct with either GSTM1 (in figure a) or GSTM2 (in figure b) without GSH-SF treatment, C+, plasmid construct with GSH-SF treatment). ii) Western blotting analysis of GSTM1 in the siRNA-treated HeLa cells. iii) Western blot analysis of GSTM2 in siRNA-treated HeLa cells. iv) GFP profile of transfected HeLa cells after siRNA treatment. All the blots are representative cropped images and every set have been processed under similar conditions as detailed in the methods section.