Moreover, immunohistochemistry (IHC) analysis of IGFBP1 expression in primary tumors from lung adenocarcinoma patients with or without metastatic recurrence further confirmed that the tumors from the patients with recurrence had higher expression of IGFBP1 than those from the patients without (Figure S1G, Supporting Information). Here, IGFBP1 is linked to lung adenocarcinoma.