In order to estimate at which EGFR expression levels this spontaneous amplification in EGFR phosphorylation can occur, we determined the level of CONEGI expression in relation to endogenous EGFR expression in non-tumorigenic epithelial MCF10A (~1 × 105 receptors/cell) and epidermoid carcinoma A431 cells (~1 × 106 receptors/cell)34–36. This evidence concerns the gene EGFR and squamous cell carcinoma.