To determine whether the presence of the PR-PPD could inhibit EGF-mediated NSCLC cell growth, A549 NSCLC cells were treated with 50 ng/ml EGF alone or in combination with 0–2.5 μM of the BR2-PPD, BR2-2xPPD, or BR2-2xΔPPD peptides. This evidence concerns the gene PGR and non-small cell lung carcinoma.