ACKR3 and prostate cancer: Further IF analyses in 22Rv1, PC-3, and DU145 prostate-cancer cells showed that CXCR7 was localized to the membrane-cytoplasmic and nuclear compartments (Additional file 1: Figure S1.D, I-I, II-I, and III-I), whereas in DU145 prostate-cancer cells it was restricted to the nuclear compartment (Additional file 1: Figure S1.D, II-I).