Hepatic mRNA levels of GSTM1, GSTM2, and GSTM4 in patients with cholestasis were decreased to 38%, 46%, and 43% of control, respectively (p<0.05 for all), while GSTM3 and GSTM4 mRNA levels were not significantly changed (Fig. 2A). This evidence concerns the gene GSTM2 and cholestasis.