ALK and neuroblastoma: ALKm were found in 13.9% of cases at the studied exonic regions harboring known ALK mutational hotspots.17,24 This is higher than previously reported frequencies of ALKm in HR-NB of approximately 10%, most likely as previous reports using Sanger sequencing or standard-resolution NGS approaches.24,26 Sanger sensitivity is limited to the detection of MAF > 15%-20%, but in NB, ALK mutations with lower MAFs have been reported.14,19-21