Concerned that some institutions would not be able to conduct a comprehensive molecular testing, cIMPACT Working Committee recommended (Louis et al., 2018) that 1p/19q testing can be omitted if an IDH-mutant tumor appears clearly astrocytic and the ATRX/p53 immunohistochemistry results are consistent with an astrocytic genotype (ATRX and/or TP53 mutations). This evidence concerns the gene IDH1 and neoplasm.