In addition, novel biomarkers, such as serum interleukin-27 (IL-27), gas chromatography–mass spectrometry (GC-MS) metabolomics, and serum reactive oxygen species modulator 1 (ROMO1), have been proposed as potential indexes for diagnosing lung cancer-associated MPE, but only a few were routinely detected in clinical practice (18, 37–39). This evidence concerns the gene ROMO1 and lung cancer.