SDHB and neoplasm: Sanger sequencing screening of this tumor did not reveal any novel mutations in SDHB and SDHD. However, mutations could have been missed due to the poor DNA quality, resulting in sequences that could not be analyzed, and due to other driving mechanisms, such as promoter-methylation or large (exon) deletions, which are not detectable by Sanger sequencing [14,15,16].