VDR and breast carcinoma: This is in good agreement with observations in mouse fibroblasts and rat intestinal epithelial cells [30], the human breast cancer cell line T-47D [32], the human osteoblastic sarcoma cell line MG-63 [33], and the human keratinocyte cell line HaCaT [22], in which 1,25(OH)2D3 up-regulated VDR protein expression 2-3-fold without affecting VDR mRNA expression.