VHL and nonpapillary renal cell carcinoma: To investigate whether the pronephros of vhl−/− zebrafish larvae recapitulates this feature of human ccRCC, we stained 4.5, 5.5 and 8.5 dpf vhl−/− and wt sibling larvae with BrdU, a nucleoside analog which is incorporated into DNA during the S phase and therefore indicates cell proliferation.