Previous research in a similarly sized cohort of patients with paired primary and matched metastatic tumour samples, identified somatic copy number losses at 9p21 (CDKN2A) and 14q (L2HGDH, HIF1A) as critical molecular alterations towards the development of metastatic disease in patients with ccRCC [5]. This evidence concerns the gene HIF1A and nonpapillary renal cell carcinoma.