During her postdoc training, Hong Ji, PhD, applied microarray approaches to study DNA methylation in a genome-wide scale and its role in regulating gene expression. Dr. Ji identified the methylome maps of hematopoietic progenitor cells and demonstrated the dynamic methylation changes during myeloid and lymphoid commitment in hematopoiesis, evocative of Waddington’s illustration of epigenetic landscape in development. The methylome maps she generated successfully assessed the lineage memory of induced programmed stem cells (iPS) derived from blood cells, which provides a valuable cool to evaluate to what extent iPS cells are reprogrammed compared to ES cells. In collaboration with biostatisticians, Dr. Ji provided a novel web platform with which the methylation status of any genomic locus of interest can be easily queried to generate output methylation plots, greatly facilitates the general accessibility of these datasets and identification of novel regulators of hematopoiesis. Her findings also explained the therapeutic specificity of DNA demethylating drug treatment of myelodysplasia, in which malignant cells arrested in early development may be induced to differentiate by DNA demethylation.