In IDH‐mutant astrocytoma, IPS differences were attenuated: PD‐1–positive comparisons trended higher in TMEM106A‐high (ctla4_neg/pd1_pos and ctla4_pos/pd1_pos, p ≈ 0.09), whereas PD‐1–negative contrasts were null (both p = 0.57). Here, IDH1 is linked to astrocytoma (excluding glioblastoma).