(A) The basic promoter region of the sFRP-4 gene has TATA-box located 38 bases upstream of the transcription start site, around which CpG dinucleotides are clustered (shown in boldface). (B) Twelve independent bisulfite mappings. Corresponding to the repression of the sFRP-4 gene expression in steady-state ST2 cells, CpGs within the mouse sFRP-4 gene basic promoter, especially upstream of TATA-box, are highly methylated. (C) The effect of 2 nM of 5-aza-dC treatment for 72 hr on steady-state sFRP-4 expression. Although not markedly prominent, quantitative RT-PCR showed that the steady-state expression of sFRP-4 was, albeit two-fold at most, significantly restored by 5-aza-dC treatment. The statistical significance was determined by Student’s t test, *P<0.05.