IDH1 and neoplasm: Tumor volume, on the other hand, showed an inverse correlation with MMSE concentration-calculation subtest performance (r = −.401, p < .01), TMT B (r = −.328, p < .01) and COWAT phonemic score (r = −.599, p < .01); however, only for the IDH1 wild-type group and not for the IDH1 mutant one (r = .060, p = .791; r = −.023, p = .345, and r =.110, p = .89).