In vivo, simultaneous co-injection of primary breast cancer cells and ASCs into nude mice suggested ASCs did not differentiate into adipocytes (Additional file, Figure 2, H&E), rather integrated into the tumor stroma, exacerbating tumorigenicity of primary breast cancer cells, which formed tumors increased in size and highly vascularized, although breast cancer cells phenotype, in terms of hormonal receptors, remained unchanged (Additional file, Figure 4). This evidence concerns the gene NR4A1 and breast cancer.