FBL and nonpapillary renal cell carcinoma: To systematically investigate the role of mitomiRs in ccRCC, we isolated mitochondria and the corresponding control components from ccRCC cell line 786O and a control human renal epithelial cell line 293T, as illustrated in Figure 1A. The purity of the isolated organelle components was further validated using their specific protein and RNA markers: mitochondria (proteins: cytochrome C, citrate synthase (CS); RNAs: lncND6, lncCYTB), cytosol (protein: tubulin; RNA: GAPDH), and nuclei (protein: fibrillarin; RNA: NEAT1) (Figure 1B,C and Figure S1A,B).