(A) Schematic diagram showing the sequence encompassing the CpG islands within the proximal 5′-regulatory region of human GP6. The CpG sites are indicated in bold and numbered consecutively in the 5′ to 3′ direction. The sequences of the flanking primer pairs used to amplify each CpG-rich segment are underlined. (B) Methylation status of the GP6 CpG island in human cord blood mononuclear cells (left) or enriched CD41⁺ cells (right). In each grid, each CpG site is represented by a column and indicated at the top, while individual cloned DNA sequences are represented by rows and numbered to the left. ▦ indicates methylated CpG sites; □, unmethylated sites. Numbers at the top correspond to the same CpG sites shown in panel A. In MNC precursors, 16 (89%) of 18 clones showed methylation at 7 or more of the 10 sites; and in the CD41⁺-enriched population, only 4 (22%) of 18 clones showed methylation at 8 or more sites.