Frequent intra-tumoural heterogeneity of promoter hypermethylation in malignant melanoma - Rastetter, Matthias; Schagdarsurengin, Undraga; Lahtz, Christoph; Fiedler, Eckhard; Marsch, Wolfgang Christian; Dammann, Reinhard; Helmbold, Peter (Histology and histopathology, 2007)