HLF was detected in both normal kidney cell lines and ccRCC cell lines by RT-qPCR, and although not all ccRCC cell lines displayed lower HLF expression compared with normal cells, we were intrigued by our observation that ccRCC cell lines lower in HLF (Caki-1, 786-O and A498) can migrate in 3D collagen compared to other ccRCC cell lines (UMRC2 and UMRC6) (Fig. 3f, g), This suggests a negative correlation between HLF level and migration ability in collagen. This evidence concerns the gene HLF and nonpapillary renal cell carcinoma.