IDH1 and pleomorphic xanthoastrocytoma: Total methylation was lowest in H3G34R/V (median beta value 0.452), and highest in the IDH subgroup (median beta value 0.520), as reported previously (Sturm et al., 2012); however it was also found to be significantly elevated in PXA-like tumors (median beta value 0.501, p < 0.0001 t test) (Figure S2C).