CCND1 and neuroblastoma: However, it is known that VPA and its active toxic metabolites can reduce the expression of the up-regulated gene 4/up-regulator of cell proliferation URG4/URGCP (URG4/URGCP) and CCND1 (Cyclin D1) genes and suppress the proliferation of neuroblastoma cells is a human-derived line cell used in scientific research SHY5Y [27,92,93].