The culture of patient‐derived breast tumor organoids cultured in MPS for several weeks revealed the hallmark features of tumor progression including angiogenesis and tumor cell intravasation.[167] They also compared the angiogenic responses of breast cancer‐associated fibroblasts (CAFs) and normal fibroblasts (NFs) and found that proangiogenic factors, such as vascular endothelial growth factor (VEGF) and TGF‐β, were significantly increased in CAFs‐co‐cultured cases compared to NFs‐co‐cultured cases. Here, TGFB1 is linked to neoplasm.