Helotonio Carvalho1. 1. Department of Biophysics and Radiobiology, Biological Sciences Centre, Federal University of Pernambuco, Recife, Pernambuco 50670-901, Brazil; Department of Immunology, Aggeu Magalhães Institute (IAM), Oswaldo Cruz Foundation (FIOCRUZ), Recife, Pernambuco, Brazil. Electronic address: helotonio.carvalho@ufpe.br.