The Waardenburg syndrome type 4 gene, SOX10, is a novel tumor-associated antigen identified in a patient with a dramatic response to immunotherapy.

In this study, we have identified, for the first time, the presence of de novo cellular immune reactivity against the transcription factor SOX10, using tumor-infiltrating lymphocytes obtained from a patient who experienced a dramatic clinical response to immunotherapy. SOX10 acts as a critical transactivator of tyrosinase-related protein-2 during melanoblast development and a potent transactivator of micropthalmia-associated transcription factor, which is considered to be a master gene that controls the development and postnatal survival of melanocytes. Mutations in SOX10 result in Waardenburg syndrome type 4. The overlapping epitopes AWISKPPGV and SAWISKPPGV, designated SOX10: 332-340 and SOX10: 331-340, respectively, were recognized by tumor-infiltrating lymphocyte clone M37 in an HLA-A2-restricted fashion.