Further confirmatory and descriptive tests are performed on tumour samples by using immunohistochemistry and molecular analyses,16,30–32 including the combined loss of chromosome arms 1p and 19q, the mutation and/or expression of p53, the presence of isocitrate dehydrogenase 1 (IDH1) mutation (within exon 4 to codon 132, the most common being c.395 G > A (R132H) substitutions33) and epigenetic alterations, such as O6-methylguanine-DNA methyltransferase (MGMT) hypermethylation.9,32. Here, IDH1 is linked to neoplasm.