HIF1A and nonpapillary renal cell carcinoma: Belzutifan inhibits HIF-2α/1β, but not HIF-1α/1β, dimerization by specifically binding to the dimerization domain of HIF-2α (Figure 3—figure supplement 1A), and thus has been used as an HIF-2α inhibitor for ccRCC treatment (Wallace et al., 2016; Xu et al., 2019).