We used two clear cell RCC (ccRCC) lines, 786-O which harbours amutation in von Hippel-Lindau (VHL) and CAKI-2 which expresses wild-type VHL, asthis is the most common mutation in patients with ccRCC.29 We tested drug efficacy in 2D monocultures and tumouroids where we focused onengineering three elements of the biophysical cancer niche. Here, VHL is linked to nonpapillary renal cell carcinoma.