CXCR4 and pancreatic ductal adenocarcinoma: This study demonstrated that CXCR4 inhibition increased the abundance of tumor infiltrating lymphocytes into metastatic lesions from patients with microsatellite stable colorectal cancer and pancreatic ductal adenocarcinoma, sensitizing these tumors to checkpoint blockade.85 Currently, little is known about the functional impact of differential CXCR4 signaling in osteosarcoma and the subsequent effects on the structure and function of different spatial distinct microenvironments in metastatic disease.