ASS1 and hepatocellular carcinoma: We also measured ASS1 mRNA expression in tumor spheroids from six Asian patient-derived HCC lines (SUN449, SUN475, SNU878, AMC-H1, AMC-H2, and Huh7), three Caucasian patient-derived liver cancer lines (Hep3B, Huh6, and adenocarcinoma line; SK-Hep1), and normal hepatocyte (Fa2N-4).