CXCR4 and neoplasm: Here, we found C-X-C chemokine receptor type 4 (CXCR4) can be a marker for PD-associated gastric CSCs and demonstrated that TGF-β enhances the efficacy of anti-tumor drugs via induction of cell differentiation /asymmetric cell division in the CXCR4+ CSC population even in a dormant state.