CHST4 and hepatocellular carcinoma: Nonetheless, these observations in cell lines do not exclude the possibility that the expressions of TBX15 and CHST4 are altered in some patients with HCC due to promoter hyper-methylation, particularly as the Western blot analysis of the 8 paired samples described above revealed that TBX15 levels were reduced in 7 of 8 tumors, and CHST4 levels were decreased in 5 of 8 tumors (Fig. 3c, d).