However, the molecular mechanisms involved in ccRCC metastasis remain to be fully understood, although it is known that the epithelial-to-mesenchymal transition (EMT) plays a central role in driving cancer metastasis, whereas snail family transcriptional repressor 1 (Snai1), a member of the Snail family of transcription factors, is key to the regulation of EMT [10–14]. Here, SNAI1 is linked to nonpapillary renal cell carcinoma.