Among primary cTCL cases sequenced in the current analyses, we found that MET, KDR, STK11 and BRAF were the most frequent somatic mutations with SMAD4, TET2, PTEN, ATM, EGFR, JAK1, MYC, NOTCH1, SMO, TP53 and PLCG1 mutated less often. This evidence concerns the gene TET2 and primary cutaneous T-cell non-Hodgkin lymphoma.