An unexpected finding of our study was that CXCR7 was present in the nucleus, in both androgen-sensitive (i.e., LNCaP, 22Rv1) and androgen refractory (i.e., PC-3, DU145) human prostate-tumor cells (Figure 2B, and Additional file 1: Figure S1.D). This evidence concerns the gene ACKR3 and prostate neoplasm.