We report a gene amplification of 25-hydroxyvitamin D3 1,alpha-hydroxylase and the appearance of various splice variants in glioblastoma multiforme. Some protein products of the widespread expressed variants may exert a biological function. The analysis of amplification and overexpression of alternative transcripts will provide new insights in the regulation of the 25-hydroxyvitamin D3 1,alpha-hydroxylase expression and may have implications for prognosis in glioblastoma.