Although little is known about the survival conditions of DTCs in the BM, some DTCs have been shown to have stem cell characteristics with the ability of self-renewal [71,72], and we recently demonstrated that early-stage-diagnosed BC patients harboring DTCs expressing the chemokine receptor type 4 (CXCR4) and the transcription factor JUNB had a higher risk for relapse [73]. This evidence concerns the gene CXCR4 and breast cancer.