A small molecule called KCN-1, reported to inhibit the HIF-1α/p300 interaction, was identified through high-throughput cell-based screening of a combinatorial library,105 with several SAR studies carried out in follow-up.106 KCN-1 has been shown to prevent HIF-regulated expression and reduce tumour size in animal models but the exact mode of action still remains unclear.107 In our hands, there was no evidence that this molecule inhibited the HIF-1α/p300 interaction in a fluorescence anisotropy competition assay.108. This evidence concerns the gene KCNA10 and neoplasm.