TGFB1 and small cell lung carcinoma: According to the significant genes from the significant pathway and DO analysis, we next focused on the DEGs in the cell cycle pathway, pathways in cancer, transcriptional misregulation in cancer, small-cell lung cancer, the MAPK signalling pathway, the TGF-β signalling pathway and non-small-cell lung cancer, and the corresponding significant genes were mapped to the corresponding molecular interaction database (Fig. 5a).