Bromodomain-containing protein 4 (Brd4)–cyclin-dependent kinase-9 (CDK9)–mediated, complete Freund’s adjuvant (CFA)–enhanced voltage-gated sodium channel 1.7 (Nav1.7) currents in dorsal root ganglia (DRG) neurons. (A) Representative traces of total Nav currents and ProTx-II–resistant currents recorded from DRG neurons dissected 1 day after intraplantar saline (saline 1d) or CFA injection (CFA 1d) with missense small interfering (si)RNA (MS RNAi + CFA 1d, 10 μl, 5 μg, intrathecally [i.t.]), Brd4-targeting siRNA (Brd4 RNAi + CFA 1d, 10 μl, 5 μg, i.t.), CDK9-targeting siRNA (CDK9 RNAi + CFA 1d, 10 μl, 5 μg, i.t.), Veh (CFA 1d + Veh, 10 μl), or JQ1 (CFA 1d + JQ1, 10 μl, 100 μM). Peak currents were elicited by voltage step from –60 to –20 mV before (black line) and after (gray line) bath application of ProTx-II (5 nM). Scale bar = 200 pA, 5 ms. Veh = vehicle. JQ1 is an inhibitor of bromodomain and extraterminal (BET) binding to acetylated histones. (B) The normalized peak values of the Nav1.7-dependent current densities (subtract ProTx-II–sensitive current from control; pA/pF) recorded from groups. **P < 0.01 versus saline 1d; ^##P < 0.01 versus CFA 1d; n = 4 to 6.