..., S. , Rakyan, V. ( 2008 ) The methylome: Approaches for global DNA methylation profiling . Trends Genet. 24 : 231 – 237 . ↵ Bell, A.C. , Felsenfeld, G. ( 2000 ) Methylation of a CTCF-dependent boundary controls imprinted expression of the Igf2 gene . Nature 405 : 482 – 485 . ↵ Bernstein, B...