To verify the difference in UBA1/6 expression, we analyzed the transcriptional expression of both genes in various tumor cell lines from two common cancers (COAD and KIRC) and normal cells using qRT-PCR experiment, and the result suggested that UBA1 was highly expressed in COAD and KIRC cell lines compared with matched normal cells, while UBA6 was only highly expressed in 786-O cell, compared to normal tubular epithelial cells (Figures 3A, B). Here, UBA6 is linked to cancer.