[Genetic alterations in new category of Peripheral T-cell lymphoma, not otherwise specified]

Peripheral T-cell lymphomas (PTCLs) are mature T-cell and natural killer (NK) cell neoplasms with poor prognosis and no available standard treatment. The 2016 revision of the World Health Organization classification of hematological malignancies recognized a new group of nodal T-cell lymphoma with T follicular helper cell phenotype due to the presence of a group of PTCLs, not otherwise specified. This new subgroup of tumors showed clinical and molecular similarities with angioimmunoblastic T-cell lymphoma (AITL). AITL patients have mutations in the Vav guanine nucleotide exchange factor-1 (VAV1) gene. We established a transgenic mouse model harboring VAV1 gene mutation. These mice developed tumors that mimic human T-lymphoblastic lymphoma and the newly proposed PTCL-GATA3 subtype. To develop personalized treatment strategies by analyzing subgroup-specific mouse models, our study supports the establishment of PTCL subgroups based on genetic alterations or gene expression profiles.