Western blot analysis of TIMP4 was performed by loading 20 µg of Raji (lane1), HeLa (lane2), Jurkat (lane3) and MDA-MB-231 (lane4) cell lysates using Novex®NuPAGE®4-12% Bis-Tris gel (Product # NP0321BOX), XCell SureLock Electrophoresis System (Product # EI0002), Novex® Sharp Pre-Stained Protein Standard (Product # LC5800), and iBlot® Dry Blotting System (Product # IB21001). Proteins were transferred to a nitrocellulose membrane and blocked with 5% skim milk for 1 hour at room temperature. TIMP4 was detected at ~25 kDa using TIMP4 Recombinant Rabbit Monoclonal Antibody (Product # 701317) at 1 µg-3 µg/mL in 2.5% skim milk at 4°C overnight on a rocking platform. Goat anti-Rabbit IgG-HRP Secondary Antibody (Product # G-21234) at 1:5000 dilution was used and chemiluminescent detection was performed using Pierce™ ECL Western blotting Substrate (Product # 32106).