Schematic representation of the methylation analyses at the 22 CpG sites within the RARB2 P2 promoter in H-596 cells. Top DNA from untreated H-596 cells; Bottom H-596 cells following 5-azadeoxycytidine treatment (fully demethylated). Each sample was derived from an independently bisulfite-treated DNA sample (only one bacterial colony is sequenced per bisulfite reaction to ensure that sequencings are not derived from the same PCR DNA template). Boxes represent CpG sites. Solid box methylated; empty box not methylated; hatched box status unavailable.