Drug experimentation to find therapeutics for breast cancers is heavily reliant on the use of in vivo animal models. This has ethical/cost issues and translational limitations due to the comparative biology of laboratory animals to the human body. Another obstacle that drug discovery must overcome is that it is becoming more apparent that each patient with breast cancer can show distinct differences in pathology and drug efficacy. We aim to recapitulate the adult stem cell and cancer stem cell niches found within the mammary gland by progressing an already established 3D in vitro model1. Murine stem cell niche capabilities have been investigated using primary stem cell enriched basal epithelial cells derived from K14-creERT2;ROSA26-tdTomato transgenic mice that have been successfully cultured within the model. Humanization of the model has begun through the use of a human mammary epithelial cell line (HMLE) whereby we have reproduced histological structures bearing some similarities to that of the native gland. Tumour invasion assays have been piloted using murine primary tumours segmented and point seeded into specially designed 3D collagen scaffolds. The human breast cancer cell line MDA-MB-231 has also been seeded into such scaffolds and cancer migration imaged using confocal microscopy. It is intended that such a model will be used to grow a number of small cancer biopsies from a patient followed by subsequent testing of a number of therapeutics. This would result in the selection of the most effective treatment for that individual i.e. personalized medicine. Ultimately the successful model could reduce animal model use for stem cell research, increase clinical relevance through humanization, provide an alternative to drug screening and in vivo cancer research whilst providing a powerful versatile analytical tool for many other fields of medical research.