It has been shown that the EWSR1/ATF1 fusion protein is able to bind to and activate the melanocyte-specific microphthalmia-associated transcription factor (MiTF); this, in the presence of the sox10 transcription factor, determines the expression of the melanocytic phenotype and regulates the growth and survival of clear cell sarcoma. The gene discussed is MITF; the disease is clear cell sarcoma.