miR-221 was additionally suggested in the regulation of HIF-1α, which plays a major role in RCC pathogenesis (Penolazzi et al., 2019), and beyond that, it could enhance RCC cell proliferation, migration, and invasion by targeting the tissue inhibitor of metalloproteinases 2 (TIMP2) as found in cell culture models (Lu et al., 2015). Here, HIF1A is linked to renal cell carcinoma.