STAT3 expression was significantly lower in tumours than in non-tumour tissue (Fig. 3d); this was surprising for us but it is again consistent with the data in the protein atlas, showing that STAT3 expression is weak in cancer in general and undetectable in 40–83% of HCC samples with 4 out of 5 antibodies used (http://www.proteinatlas.org/ENSG00000168610-STAT3/cancer/tissue/liver+cancer). This evidence concerns the gene STAT3 and cancer.