Given that eAGR2 is secreted by tumor organoids (Figure 5A) and that AGR2 has been reported in the serum of cancer patients with an average level of eAGR2 ranging from 0.5 to 20 ng/ml (Chen et al., 2010), we assessed whether eAGR2 might exhibit specific extracellular functions. This evidence concerns the gene AGR2 and cancer.