PLCG1 and adult T-cell leukemia/lymphoma: PLCG1 mutations have also been detected in other mature T-cell malignancies, notably HTLV-1 associated ATLL (25), PTCL(NOS) (26), hepato-splenic T-cell lymphomas (27) and AITL (28) with the PLCG1 p.S345F and R48W variants being two of the most frequently reported.