IDH2 and mature T-cell and NK-cell non-Hodgkin lymphoma: Although the variant allele frequencies of the TET2 and DNMT3A genes were higher than that of the RHOA gene, we found six RHOA gene-mutated cases that had no other mutations in TET2, DNMT3A or IDH2. In the present series, all IDH2-mutated cases also had RHOA gene mutations that were present in the AITL and PTCL-NOS patients.