CCR2 and pancreatic ductal adenocarcinoma: CCR2 was over‐expressed in breast cancer, pancreatic ductal adenocarcinoma, and prostate cancer, which played a crucial role in tumor metastasis and development by maintaining the hyperplasia and tumor cells’ survival, stimulating the migratory and invasive ability of cancer cells, and inducing inflammatory response and angiogenesis.28, 29, 30