EGFR and cancer: EGFR is cis-inhibited through autoinhibitory interactions centered around the rotation of the αC-helix and is released by the asymmetric dimer interface and the activating mutations observed in cancers for EGFR are dominated by two mutations accounting for ∼4500 of the 5000 or so total mutations (Figure 2): a point mutation (L834R) within the hydrophobic core as well as a small in frame deletion at least involving residues 747 to 751, at the tip of the αC-helix.