POLD1 and central nervous system cancer: In the CNS LS-related tumor group, 6 glioma samples (PLS041, PLS046, PLS124, PLS143, PLS185, PLS228) had a TMB greater than 300 but were MSS, and we found each patient harboring mutations in the DNA polymerase genes, POLE or POLD1, which are associated with a hypermutated phenotype.