IGFBP1 and lung adenocarcinoma: In addition, we carried out ELISA assay to examine IGFBP1 protein levels in blood samples from lung adenocarcinoma patients and compared blood IGFBP1 levels between the patients with or without metastatic recurrence, which showed that the patients with recurrence had higher IGFBP1 levels in blood than those without (Figure S1I, Supporting Information).