BETting on stem cell expansion

For decades, the expansion of hematopoietic stem cells (HSCs) has been an elusive goal. In this issue of Blood, Hua et al took a step toward reaching this goal by demonstrating that the addition of the small molecule bromodomain and extra-terminal motif (BET) inhibitor CPI203 to a cytokine cocktail results in expansion of serially transplantable long-term repopulating HSCs (LT-HSCs). They also showed enhancement of their potential to differentiate into megakaryocytes (MKs).(1