More importantly, compared with control group, the BE-EAC group had decreased sera exosomal expression levels of miR-15a, -15b, -16, and -193a-3p from BE status to their EAC progression (Figure 5), suggesting that these exosomal microRNAs could be not only early biomarkers for EAC development in BE patients, further differential expressed microRNAs in Barrett’s esophagus may target PD-L1 expression and contribute to the development of esophageal adenocarcinoma. Here, CD274 is linked to Barrett esophagus.