ccRCC 2D cultures (from Grade 2 and 3 tumours) were also established in serum-supplemented DMEM, with over 90% of cells expressing cytokeratin, vimentin and CD13, and over 60% of cells positive for carbonic anhydrase IX (CA9), a marker specific for ccRCC. Here, ANPEP is linked to nonpapillary renal cell carcinoma.