Western blot was performed using Anti-GDF15 Polyclonal Antibody (Product # PA5-17066) and a ~34 kDa band corresponding to GDF15 was observed across the cell lines tested except Jurkat which is reported to be negative. The expression of protein also increased in HCT 116 upon thapsigargin treatment. Whole cell extracts (30 µg lysate) of LNCaP (Lane 1), LNCaP treated with PTI (1X for 4 hr) (Lane2), HCT 116 (Lane 3), HCT 116 treated with PTI (1X for 4hr) (Lane 4), HCT 116 treated with thapsigargin (16 µm for 16hr) and PTI (1X for 4 hr) (Lane 5), Jurkat (Lane 6) and Jurkat treated with PTI (1X for 4hr) (Lane 7) were electrophoresed using Novex® NuPAGE® 4-12 % Bis-Tris gel (Product # NP0322BOX). 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 (1:1,000 dilution) and detected by chemiluminescence with Goat anti-Rabbit IgG (Heavy Chain) Superclonal™ Recombinant Secondary Antibody, HRP (Product # A27036, 1:4,000 dilution) using the iBright FL 1000 (Product # A32752). Chemiluminescent detection was performed using Novex® ECL Chemiluminescent Substrate Reagent Kit (Product # WP20005).