AKT1 and breast carcinoma: To determine the role of the IQ3 motif in the activation of the PI3K-Akt pathway, human embryonic kidney (HEK293FT), human HNC (UM-SCC47, HPV-positive), and human breast carcinoma cells (MDA-MB-231) were transiently transfected with plasmids expressing GFP-tagged wild-type IQGAP1 (IQGAP1WT) or IQ3 (aa806–825)-deleted IQGAP1 (IQGAP1∆IQ3) (Fig. 1a) and Akt phosphorylation was measured in response to EGF stimulation.