DNMT3A and neuroblastoma: The effect of 1,25-Dihydroxyvitamin D3 on the viability of human neuroblastoma human neuroblastoma cell line cells was investigated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide assay, the effect on migration was investigated by wound healing assay, and methyltransferase genes (DNA methyltransferase 3 alpha and DNA methyltransferase 3 beta) and phosphatase and tensin homolog gene expression levels were investigated by real time polymerase chain reaction method.