The presence of a humanised haematopoietic system might affect the bone formation rate, as the CD34+ cells are implanted together with the scaffold containing hOBs We intended for this model to allow the study of interactions between the tumour and the bone cells, as bone is a frequent site of metastasis for a number of cancers [36], and in some cases, tumour cells directly interact with the bone cells. The gene discussed is CD34; the disease is cancer.