HIF1A and nonpapillary renal cell carcinoma: Using the non-altered genes of lamin A/C (LMNA) and upstream stimulatory factor 1 (USF1) as DNA-loading controls, and genomic DNA from normal kidney epithelial HK2 cells as a normal DNA copy number control, most HIF1α-defective ccRCC cell lines were found to have loss of one HIF1A allele and loss of several exons of the second allele of the HIF1A gene (Figure 1c and Supplementary Figure 1).