Unlike 2D cultures, this 3D model showed an increase in expression of fibroblast growth factor 23 and alkaline phosphatase, accurately depicting the bone niche observed clinically in metastatic PCa.106 The use of polymer‐nanoclay‐based 3D scaffolds for the growth and study of PCa cells in coculture with MSCs yielded the formation of tumoroids with tight cellular junctions and hypoxic cores. Here, FGF23 is linked to posterior cortical atrophy.