Western blot analysis was performed on membrane enriched extracts (30 µg lysate) of MCF7 (Lane 1), A-431 (Lane 2), H1975 (Lane 3), PC-3 (Lane 4), DU-145 (Lane 5), MDA-MB-231 (Lane 6), Ramos (Lane 7), HEK-293 (Lane 8), 3T3-L1 (Lane 9), Jurkat (Lane 10) and A549 (Lane 11). The blots were probed with Rabbit Anti-GRB2 Polyclonal Antibody (Product # PA5-17692, 1:1000 dilution) and detected by chemiluminescence using Goat anti-Rabbit IgG (Heavy Chain) Superclonal™ Secondary Antibody, HRP conjugate (Product # A27036, 0.25 µg/mL, 1:4000 dilution). A 25 kDa band corresponding to GRB2 was observed across the cell lines tested. Known quantity of protein samples were electrophoresed using Novex® NuPAGE® 12 % Bis-Tris gel (Product # NP0342BOX), XCell SureLock™ Electrophoresis System (Product # EI0002) and Novex® Sharp Pre-Stained Protein Standard (Product # LC5800). Resolved proteins were then transferred onto a nitrocellulose membrane using iBlot® 2 Dry Blotting System (Product # IB21001). The membrane was probed with the relevant primary and secondary antibody following blocking with 5 % skimmed milk. Chemiluminescent detection was performed using Pierce™ ECL Western Blotting Substrate (Product # 32106).