Based on the workshop cases and recent literature, the mutational landscape of primary nodal-EBV-TNKL is similar to cPTCL-NOS and is characterized by frequent mutation of epigenetic modifiers, such as TET2 and DNMT3A, and JAK/STAT pathway genes suggesting a potential role of CH and JAK/STAT pathway in the pathogenesis of cytotoxic PTCL. Here, C4B is linked to mature T-cell and NK-cell non-Hodgkin lymphoma.