BAG3 and cancer: BAG3 is up‐regulated in cancer cells and its overexpression is correlated with tumour progression and poor prognosis of PDAC.22, 23 Recent study has demonstrated that BAG3 can be secreted by PDAC cells and secreted BAG3 promotes pancreatic ductal adenocarcinoma proliferation via activating stromal macrophages in tumour microenvironment.20 Previous reports have mainly highlighted the oncogenic role of BAG3 highly expressed by cancer cells themselves.