Antibodies used were mouse anti-TBP (ab818, Abcam, UK), mouse anti-GAPDH (ab8245, Abcam, UK) and rabbit anti-KCNAB2 (LSBio; LS-C30846, USA). Protein signals were detected and quantified by SuperSignal West Pico Chemiluminescence Substrate (Thermo Scientific, USA) on the Vilber Fusion-FX Chemiluminescence System (Vilber Lourmat, USA).