Several studies show that RHOA and IDH2 mutations are strongly associated with the TFH immunophenotype and more extensive characteristics typical of AITL such as proliferation of follicular dendritic cells, high endothelial vessels, and presence of clear cells, with IDH2 mutation defining a unique subgroup of AITL 12, 45, 46, 47. This evidence concerns the gene IDH2 and angioimmunoblastic T-cell lymphoma.