Mechanistically, the BET family of proteins control a diverse array of cellular processes6 and more preclinical work needs to be done prior to elucidation of the appropriate clinical context wherein BET inhibitors may be best utilised.25 The results of this trial herein, and emerging data from other Phase 1 studies of BET inhibitors in solid tumours, suggest that achieving a therapeutic window where an anti-tumour effect can be achieved without undue adverse events due to on-target effects may be challenging with this class of agents, also making drug combinations particularly difficult. The gene discussed is DNER; the disease is neoplasm.