HIF1A and nonpapillary renal cell carcinoma: Further, the BAF180-containing SWI–SNF chromatin remodeling complex is critical for HIF1-mediated transcriptional response and BAF180 is mutated in a subset of ccRCC tumors.7, 8, 9, 10, 11, 23 These observations prompted us to test the hypothesis that BAF180 mutation is associated with HIF1A retention in H1H2 ccRCC tumors.