Western blot was performed using Anti-PAK1 Polyclonal Antibody (Product # PA5-29256) and a 60kDa band corresponding to PAK1 was observed across all the tested cell lines and tissues. Whole cell extracts (30 µg lysate) of Jurkat (Lane 1), Caco-2 (Lane 2), MCF7 (Lane 3), U-2 OS (Lane 4), MDA-MB-231 (Lane 5), HEK-293 (Lane 6), Mouse Brain (Lane 7), Rat Brain (Lane 8) were electrophoresed using NuPAGE™ 10% Bis-Tris Protein Gel (Product # NP0302BOX). 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 with Goat anti-Rabbit IgG (Heavy Chain) Superclonal™ Recombinant Secondary Antibody, HRP (Product # A27036,1:4000) using the iBright FL 1000 (Product # A32752). Chemiluminescent detection was performed using SuperSignal™ West Dura Extended Duration Substrate (Product # 34076).