[{"from": "human", "value": "Provide a brief overview of this molecule. [C][C@H1][Branch1][#C][/C][=C][/C@H1][Branch1][C][C][C][Branch1][C][C][Branch1][C][C][O][C@H1][C][C][C@@H1][C@@][Ring1][Branch1][Branch2][Ring1][#Branch1][C][C][C][/C][\\-Ring1][=Branch1][=C][\\C][=C][C][C@H1][Branch1][=Branch2][C][C@@H1][Branch1][Ring2][C][Ring1][=Branch1][O][O][C]"}, {"from": "gpt", "value": "The molecule is a synthetic noncalcemic, nonphosphatemic vitamin D analogue.  Paricalcitol binds to the vitamin D receptor and has been shown to reduce parathyroid hormone (PTH) levels. This agent also increases the expression of PTEN ('Phosphatase and Tensin homolog deleted on chromosome Ten'), a tumor-suppressor gene, in leukemic cells and cyclin-dependent kinase inhibitors, resulting in tumor cell apoptosis and tumor cell differentiation into normal phenotypes. (NCI04)"}]