According to the SMURF1 mRNA expression levels retrieved from the gene expression profile (GEO: GSE14520), we separated non-tumor liver tissue samples into the high SMURF1 expression (top 25%) group (n = 61) and the low SMURF1 expression (bottom 25%) group (n = 59) (Fig 2D, left panel). Here, SMURF1 is linked to neoplasm.