1. Department of Pathological Sciences; Biological Science Center; Laboratory of Molecular Genetic and Immunology; State University of Londrina; Londrina; PR; Brazil
2. Service of Head and Neck; Erasto Gaertner Hospital; Curitiba; PR; Brazil
3. Department of Genetic; Human Cytogenetic and Oncogenetic Laboratory; Federal University of Parana; Curitiba; PR; Brazil
4. Laboratory of Histocompatibility; State University of Londrina; Londrina; PR; Brazil