Illustration of the first bromodomain (BD1) from human bromodomain testis-specific (BRDT) protein bound to an inhibitor (NC-II-153). Bromodomains play a key role in regulating gene transcription. Deregulation of bromodomain-containing proteins is frequently seen in cancer and therefore their inhibitors are being studied as potential anticancer drugs. Inhibition of BRDT is also being studied as a target for a male contraceptive.