IL2 and metastatic neoplasm: Ultimately, we compared the enrichment degree of 50 typical pathways in primary and metastatic tumors and observed 49 pathways that were upregulated in metastasis, including the apical junction, epithelial-to-mesenchymal transition (EMT), IL2-STAT5 signaling, G2M checkpoint, E2F targets, TGF beta signaling, Hedgehog signaling, and so on (Additional file 1: Fig. S8D).