In particular, PPAT expression is one of the strongest indicators for poor prognosis in small cell lung cancer (SCLC), which is highly malignant (5-year survival rate, ~7%), with a high rate of growth and metastasis, and has been referred to as a “recalcitrant cancer”23, with no specific and effective treatment having been developed to date. Here, PPAT is linked to small cell lung carcinoma.