Tumors from 13 of 15 patients were found to have mutations that led to the R132H neomorphic phenotype in the IDH1 gene (one tumor also contained a variant mutation of uncertain significance in IDH2) and 2 of 15 patients had tumors which harbored neomorphic mutations in the IDH2 gene (R172G and R172K; Table 2). Here, IDH1 is linked to neoplasm.