To investigate the dysregulated pathways upon knockdown of PB1, we firstly focused on the AKT–mTOR signalling pathway, because AKT–mTOR is one of the most disturbed signalling pathways and a large number of ccRCC samples harbouring PB1 mutations do not have mutations of other key genes of AKT–mTOR signalling pathway such as PTEN,PIK3CA,AKT2,TSC1,TSC2,RHEB and MTOR. This evidence concerns the gene MTOR and nonpapillary renal cell carcinoma.