In univariate logistic regression analysis, SUVmax of mediastinal lymph node, SUVmax of primary tumor, SUVpeak of primary tumor, SUVmean of primary tumor, MTV of primary tumor, TLG of primary tumor, maximum diameter of primary tumor, degree of primary-tumor solidity, CEA, CYFRA21-1, CA19-9, SCC and NSE were significantly related to metastasis in mediastinal lymph nodes (Table 3 and Additional file 1: Table S2). The gene discussed is SERPINB3; the disease is neoplasm.