STING1 and mature T-cell and NK-cell non-Hodgkin lymphoma: Our findings, showing that only 7.7% of AITLs are positive for STING as compared to 79% of PTCL-NOS, provide a novel immunohistochemical marker that could be helpful in distinguishing between these two lymphoma types that may share similar morphological features, although the existing immunohistochemical and molecular methods are quite efficient for classification.