CXCL12-Abundant Reticular (CAR) Cells: A Review of the Literature with Relevance to Cancer Stem Cell Survival

The bone marrow niche is an intricate microenvironment with multiple cell types, gradient of cytokines and oxygen concentration. The niche has a substantial and intricate role in both health and disease, including the accommodation of cancer cells in the dormant phase. Since the cancer stem cells can survive as dormant cells in the bonemarrow, an understanding of the nichewould be important for hematological aswell as an understanding of cancer stemcell in a physiological situation.One of the cell types in the bone marrow is CXCL12-abundant reticular cells, commonly referred to as CAR cells. Discovered relatively recently, some progress has been made in understanding their origin and function. The function and location of the CAR cells indicate that these cells may be important therapeutic target for both hematological and oncological diseases. Since the CAR cells havebeen shown to promote andmaintain hematopoietic stemcells, further researchmaydemonstrate the sameeffectwith cancer stem cells. We review here the current literature regarding CAR cells and their potential for future research as well as the roles in bone marrow diseases, such as their role in sustaining the cancer stem cells within bone marrow.