DNA methylation data from our previously published studies on solid papillary breast carcinoma with reverse polarity (N = 5)16, and sinonasal undifferentiated carcinoma (SNUC, N = 8)12, as well as DNA methylation profiles of IDH mutant oligodendroglioma (N = 20) and astrocytoma (N = 31) profiled at NYU Langone Health from 2015 to 2018. This evidence concerns the gene IDH1 and astrocytoma (excluding glioblastoma).