NOTCH1 and neoplasm: Notably, all NOTCH1 mutations in B-cell lymphomas secondary to AITL were detected only in B cells, whereas RHOA G17V mutations were specific to all tumor T cells [8], showing that NOTCH1 mutation and RHOA G17V mutation play a role in B-cell lymphoma and AITL, respectively, and both are secondary mutations following TET2 mutation.