The human body contains except for STXBP1 also STXBP2 and STXBP3. These two proteins are highly similar to STXBP1. Therefore it is interesting to investigate whether they have similar or distinct functions. The research of Daniel focusses on the fundamental ability of brain cells to secrete peptides, such as hormones. Brain cells contain high amounts of STXBP1, but also contain moderate amounts of STXBP2. Therefore, he investigates what the roles of STXBP1 and STXBP2 are in peptide secretion.