Figure 1: Experimental scheme of the procedures used for the screening of differentially expressed proteins. After lysis and enzymatic digestion, peptides were labeled with stable isotope and the differentially dimethyl-labeled products were then analyzed after desalting and fractionation. The quantitative shotgun analysis of proteome changes from clinical samples of renal clear cell carcinoma (RCC) and normal tissues was carried out by using HILIC-C18 peptide separation and nano LC-MS/MS coupled with stable isotope dimethyl labeling.