Three medulloblastoma cell lines were unmethylated for S100A4, and were associated with higher gene expression unaffected by demethylation treatment (in contrast to methylated lines, which were associated with methylation-dependent transcriptional silencing), suggesting that they had undergone selection for hypomethylation and overexpression of S100A4 during the tumourigenic process. This evidence concerns the gene S100A4 and medulloblastoma.