Western blot was performed using Anti- CYR61 Polyclonal Antibody (Product # PA1-16579) and a ~42 kDa band corresponding to CYR61 was increased upon treating the cells with secretion blockers (FLI and PTI) in MDA-MB-231 when compared to MCF7. An uncharacterized band (*) was observed at ~ 50 kDa. Whole cell extracts (30 µg lysate) of MDA-MB-231 (Lane 1), MDA-MB-231 treated with FLI (10µM for 4 hr) (Lane 2), MDA-MB-231 treated with PTI (1X for 4 hr) (Lane 3), MCF7 (Lane 4), MCF7 treated with FLI (10µM for 4 hr) (Lane 5) and MCF7 treated with PTI (1X for 4 hr) (Lane 6) were electrophoresed using Novex® NuPAGE® 4-12 % Bis-Tris 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 (1:500 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).