ZBTB48 and Merkel cell skin cancer: TZAP is a POK family protein consisting of 11 zinc finger domains and a POZ domain, which is commonly rearranged in leukemia and leiomyoma or obliterated in various cancers, including melanoma, neuroblastoma, Merkel cell carcinomas, breast cancer, pheochromocytoma and colon carcinoma [42].