Crypt methylation before and neo-adjuvant therapy. There are eight tags per crypt with each tag arranged in a 5' to 3' horizontal order of CpG sites. CSX (eight CpG sites) and BGN (nine CpG sites) tags were sampled from eight of the same crypts. Crypt methylation patterns are summarized by percent methylation and numbers of unique tags per crypt. Methylation patterns were not significantly different before and after neo-adjuvant therapy, with averages summarize in the Table. The seemingly random methylation patterns are consistent with a model  in which stochastic methylation errors start to accumulate from birth.