Z. Fan et al. from UCLA School of Dentistry reported in the August issue of Nature Cell Biology their study on BCL-6 co-repressor (BCOR) in regulating mesenchymal stem cell (MSC) function. By studying oculo-facio-cardio-dental (OFCD) syndrome, a rare inherited human disease, the investigators uncovered a mechanism in which BCOR mutation in MSCs isolated from a patient with OFCD may be responsible for the disease. OFCD is characterized by canine teeth with extremely long roots, congenital cataracts, cranofacial defects, and congenital heart disease. The researchers identified AP-2α as the repressive target for BCOR and BCOR mutation results in abnormal activation of AP-2α. Additionally, the experimental results revealed that AP-2α is a key regulator for mediating osteo-dentiogenic capacity of MSCs. It was also found that BCOR maintained "tissue homeostasis" and BCOR mutation resulted in increased histone H3K4 and H3K36 methylation. Chromatin methylation resulted in transcription of silenced target genes and thereby demonstrates an epigenetic regulatory role for BCOR in human adult stem cell function.