Although single-agent PDE inhibitors potently stimulate growth in NSCLC, combining PDE inhibitors (PDE8i, PDE5i, PDE9i, and PDE10i) with low-dose PMX may enhance the anti-NSCLC activity of PMX in both squamous and non-squamous NSCLC cell lines. The gene discussed is ALDH7A1; the disease is non-small cell lung carcinoma.