however , the methylation pattern in the region immediately upstream and in the 5'-half of the gene exhibited tissue-specificity : the site located about 0.13 kb upstream of the cap site ( just next to the ccaat box ) , and the sites in the first intron ( intron 1 ) were heavily methylated in nonexpressing cells and tissues ( ascites hepatoma ah130 and brain ) , whereas those in an expressing tissue ( liver ) were considerably less methylated .
C0021920
intron
C0007634
cells