Western blot was performed using Anti-HEXIM1 Polyclonal Antibody (Product # PA5-78336) and 53, 35 kDa bands corresponding to HEXIM1 was observed in HeLa, A549, HEL 92.1.7, HepG2 and not in SH-SY5Y and Daudi which are reported negative for HEXIM1 expression. Modified whole cell extracts (1% SDS) (30 µg lysate) of HeLa (Lane 1), A549 (Lane 2), HEL 92.1.7 (Lane 3), Hep G2 (Lane 4), SH-SY5Y (Lane 5) and Daudi (Lane 6) were electrophoresed using Novex® NuPAGE® 4-12 % Bis-Tris gel (Product # NP0322BOX). Resolved proteins were then transferred onto a nitrocellulose membrane (Product # IB23001) by iBlot® 2 Dry Blotting System (Product # IB21001). The blot was probed with the primary antibody (1:1000 dilution) and detected by chemiluminescence Goat Anti-Rabbit IgG Secondary Antibody, HRP conjugate (Product # A27036, 1:4000 dilution) using the iBright FL 1000 (Product # A32752). Chemiluminescent detection was performed using Novex® ECL Chemiluminescent Substrate Reagent Kit (Product # WP20005).