Figure 3

Crypt methylation tags are consistent with a clock-like stochastic accumulation of methylation errors from birth. Such a model using previously published crypt parameters [4] can be simulated on a computer to yield expected individual (dotted lines include 95% of simulated crypt outcomes) and average (solid grey line) crypt values. Little difference is expected between the initial (black X 's are individual crypt values and black triangles are average values) and final specimens (red bars are individual crypt values and red circles are average values) because by this model, methylation errors slowly accumulate from birth, and few additional changes are expected to accumulate during the 62 days between specimens.