SIRT4 and hepatocellular carcinoma: Of the seven NCBI GEO datasets studied, four datasets (GSE36376, GSE39791, GSE22058, GSE25097) had a higher SIRT4 expression in the HCC tumor than their adjacent non-tumor counterparts, while the other three datasets did not show any significant difference between the tumor and non-tumor tissues (Fig. 2A, B).