Similarly, increased proliferation and invasion of MDA-MB-231 cells after exposure to bone marrow adipocyte-conditioned media was also associated with HO-1 induction in a previous study (38).While there is evidence that HO-1 upregulation led to the activation of pro-survival pathways in PCa cells, a similar mechanism remains to be demonstrated in breast cancer cells. This evidence concerns the gene HMOX1 and breast cancer.