TOP2A and lung carcinoma: Lung cancer-associated gene microarrays were obtained from GEO and TCGA datasets, and TOP2A significantly co-expressed genes (|R| > 0.6, p < 0.01, Supplementary Fig. 1A–C and Additional file 1: Table S2) were obtained from three microarrays, TCGA-LUAD, GSE19804, GSE116959, and 1111, 1194 and 247 genes were obtained, respectively.