Describes research which showed that differentially methylated regions in a specific imprinted gene can carry a crucial imprinting signal. Genomic imprinting and its loss; Role of DNA methylation; Research by Wutz et al in the October 16, 1997 edition of `Nature'; Methylation differences; Igf2r gene containing local signals for imprinting; Local control elements for imprinting Igf2r YAC; Antisense gene; Parallels between Igf2r and Igf2-H19 systems; Methylation details.