With DNA extracts from frozen tumor samples, SSCP-PCR, and direct sequencing of exons, Eibl found the first TP53 mutations in primary medulloblastoma tissue (Figure 3) [1], whereas others were unable to detect such mutations in primary tumor tissue but found one in a cultured cell line, which was assumed to have developed in the culture [42]. Here, TP53 is linked to medulloblastoma.