WT1 and leukemia: The most frequently altered genes in our cohort of patients (CDKN2A, CDKN2B, IKZF1, PAX5, PTNP11, FLT3, PTEN, CRLF2, WT1, KRAS, NRAS, PHF6, etc) have been previously reported in paediatric leukaemia [28,29,30,31,32] and are known to be involved in biological pathways related to leukemogenesis.