IDH1 and glioma: Comparisons of mutIDH1R132H/C, mutIDH2R172K/W/G, and WT IDH1 glioma, using in vivo MRS in humans, has shown that N-acetylated amino acids (NAAAs) are consistently decreased in all tumor types measured compared with healthy tissue.122, 123, 124 Orthotopic mutIDH1R132H and WT IDH1 glioma PDX mouse models similarly show lower levels of NAAAs compared with healthy tissue.99