Abstract
The tandem bromodomains (BD1 and BD2) of the BET family proteins BRD2, BRD3, BRD4, and BRDT are structurally conserved but not functionally equivalent. In this issue of Chemistry & Biology, Gacias and colleagues report that a BD1-specific chemical inhibitor, Olinone, enhances oligodendrocyte differentiation, contrasting the reverse process triggered by broad BD1/BD2-targeting inhibitors, highlighting distinct roles of BD1 and BD2 in cell fate decision.