IDH1 and pleomorphic xanthoastrocytoma: According to Yan et al.’s research, more than 80% of LGGs harbor an IDH mutation, including diffuse astrocytoma (grade II, 90%), pleomorphic xanthoastrocytoma (grade II, 14%), and anaplastic astrocytoma (grade III, 73%), whereas only 5% of primary GBMs contain IDH mutations (2, 3, 8).