ESR1 and breast cancer: Watzling et al. cultured MDA-MB-231 and MCF7 BC cells and ASC spheroids in agarose molds in direct contact to evaluate the expression of C–C motif chemokine ligand 5 (CCL5) and receptor C–C chemokine receptor type 1 (CCR1).58 Unfortunately, none of the prior studies have addressed the role of ASCs regulation of endocrine response in ER+ breast cancer using a 3D co-culture model.