Western blot and Flow Cytometry analysis revealed the same profile in 3 other breast cancer cell lines (MDA-MB361, MCF7 and T47D) and an absence of expression of CXCR4 or an absence of increase of this receptor upon co-culture with BMHC in two other one (Hs578T and SK-BR-3; Additional file 1: Figure S1B-C). The gene discussed is CXCR4; the disease is breast cancer.