VAV1 and mature T-cell and NK-cell non-Hodgkin lymphoma: More recently, the sequencing of human tumours has revealed the presence at relatively high frequencies of VAV1 mutations in peripheral T cell lymphoma (PTCL) subtypes such as angioimmunoblastic T cell lymphoma (AITL, 6% of total cases), adult T cell leukaemia/lymphoma (17% of total cases), and peripheral T cell lymphoma not otherwise specified (PTCL‐NOS, 7% of total cases).