Figure 5.

Gene set enrichment analysis of the CK19⁺ gene signature. (A) The analysis demonstrated a significant positive correlation between the CK19⁺ gene signature and the gene expression signature of subclass A and hepatoblast-like (HB) human HCCs (Red, Class A). The HB subclass was previously shown to have a fetal hepatoblast-like and progenitor-type expression signature. This subtype has the worst clinical prognosis. Several stem cell and liver specific gene sets in the Molecular Signatures Database were found among the top 10 gene sets which positively correlated with the CK19⁺ gene signature (Supplementary Table 2). (B) Association of the CK19⁺ gene signature and the stem cell module map. In this comparison, we used the genes given in the human embryonic stem cell-like module. More than 15% of the genes in the CK19⁺ gene expression signature overlapped with the module map.