WB (peptide competition) analysis of 3T3-L1 cells (Lane 1-4) or COS cells over-expressing WT AS160 (Lane 5, 6) or mutant AS160 T642A (Lane 7), treated with PI-3-Kinase inhibitor LY294002 (Lane 5) or insulin (Lane 1-4, 6-7) using GTX76675 AS160 / TBC1D4 (phospho Thr642) antibody prior incubated with the non-phosphopeptide corresponding to the phosphopeptide immunogen (Lane 2), a generic phosphothreonine-containing peptide (Lane 3), or the phosphopeptide immunogen (Lane 4) control. The data show that only the immunogen phosphopeptide blocks the signal, demonstrating the specificity of the antibody.