Participants
Thirty children diagnosed with hepatoblastoma were enrolled in this study, which was performed at the Institute of Biosciences, University of São Paulo, Brazil. Patients were recruited from five different Brazilian institutions, most of them (n=27) from three large pediatric cancer centers of the city of São Paulo, namely, the A. C. Camargo Cancer Center, Adolescent and Child with Cancer Support Group (GRAACC), and Pediatric Cancer Institute (ITACI). In addition, three patients were recruited from other institutions, including the Hospital da Baleia (n=1), Hospital da Criança Conceição (n=1), and Hospital São Lucas (n=1). This study was approved by the Research Ethics Committee of the Institute of Biosciences (CAAE: 09163818.4.0000.5464). After signed informed consent was obtained from the parents, peripheral blood samples were collected from 28 patients, and normal liver tissues were recovered from two patients. Genomic samples were also collected from 27 available parents (19 patients).