Development of breast cancer microphysiological systems. The breast cancer microenvironment can be recapitulated in vitro by combinations of primary breast tumor cells, ASC, decellularized adipose tissue, blood-derived products, including PRP, RBC, and WBC, along with cytokines and growth factors. These can serve as alternatives to PDX models that require an immunodeficient murine host. ASC, adipose-derived stromal/stem cells; PDX, patient-derived xenograft; PRP, platelet-rich plasma; RBC, red blood cell; WBC, white blood cell.