Western Blot was performed using Anti-M-CSF Polyclonal Antibody (Product # PA5-86850) and a 44 kDa band corresponding to Macrophage colony-stimulating factor 1 was observed across cell lines tested except Raji cells which are reported to be low or negative for M-CSF expression. Whole cell extracts (30 µg lysate) of SK-BR-3 (Lane 1), SK-BR-3 treated with Protein Transport Inhibitor (PTI) (1X) for 4hrs (Lane 2), Raji (Lane 3), Raji treated with PTI (1X) for 4hrs (Lane 4), MDA-MB-231 (Lane 5) and MDA-MB-231 treated with PTI (1X) for 4hrs (Lane 6) were electrophoresed using NuPAGE™ 4-12% Bis-Tris Protein Gel (Product # NP0321BOX). 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 dilution) using the iBright FL 1000 (Product # A32752). Chemiluminescent detection was performed using Novex® ECL Chemiluminescent Substrate Reagent Kit (Product # WP20005).