Sepw1 expression in livers of pI–pC-induced, mock- or cadmium-treated Mtf1Mx-cre and Mtf1loxP mice was further analyzed by semiquantitative RT–PCRs and S1 analysis (Figure 2a and b). In accordance with microarray data a slight, if any, upregulation of Sepw1 transcription was observed in livers from Mtf1loxP mice upon cadmium treatment. The basal level was reduced in livers from mock- and cadmium-treated Mtf1Mx-cre mice, indicating that MTF-1 is important for the basal expression of Sepw1.