Western Blot was performed using Anti-Acinus Polyclonal Antibody (Product # PA5-19940) and ~220 kDa, ~150 kDa, and ~75-80 kDa bands corresponding to splice forms of ACIN1 was observed across cell lines tested and downregulated upon cell treatments. Whole cell extracts (30 µg lysate) of Hep G2 (Lane 1), untreated Jurkat (Lane 2), staurosporine treated Jurkat (Lane 3), camptothecin treated Jurkat (Lane 4), untreated U-2 OS (Lane 5), etoposide treated U-2 OS (Lane 6) and HeLa (Lane 7) 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, 1:10000 dilution) using the iBright FL 1000 (Product # A32752). Chemiluminescent detection was performed using Novex® ECL Chemiluminescent Substrate Reagent Kit (Product # WP20005). Downregulation of ACIN1 splice forms upon apoptotic stimuli are seen in both Jurkat and U-2 OS cells [doi: 10.1038/emboj.2009.106; 10.1038/43678]