AGR2 and lung cancer: Its overexpression in numerous cancer types has been linked with enhanced cell migration and proliferation, altered adhesion and differentiation and promotion of angiogenesis and metastasis.36 Previous studies have found elevated tissue expression of AGR2 to be an indicator of poor prognosis,37 and it has been reported as a putative blood-borne biomarker for the detection and/or prognosis of ovarian, pancreatic, prostate and lung cancer.25,38–40 Our findings support AGR2 as a biomarker for early ovarian cancer detection that complements CA125 (and CHI3L1) when used longitudinally.