HIF1A and nonpapillary renal cell carcinoma: In kidney cancer, transcription factors, hypoxia-inducible factor 1A (HIF1A) and hypoxia-inducible factor 2A (HIF2A) are important for tumorigenesis and development of ccRCC through activating transcription of genes, such as vascular endothelial growth factor, which could impact the angiogenesis signaling pathway (Schodel et al., 2016).