DIRAS1 and central nervous system cancer: We investigated the expression of DIRAS-1 transcripts and detected decreased mRNA levels (<0.5-fold relative to non-neoplastic brain tissue) in 22 out of 34 gliomas (65%) and intermediate mRNA levels (between 0.5 and <1 relative to non-neoplastic brain tissue) in eight out of 34 gliomas (24%) (Table S1).