GK and cancer: We found that endogenous GK1 was markedly expressed at the mRNA (Figure 3A) and protein (Figure 3B) levels in human hepatocellular carcinoma HepG2 and in human prostate cancer LNCaP (androgen-dependent) cells, whereas it was not significantly expressed in other types of cancer cell lines, including human prostate cancer PC-3 and DU-145.