The VSDB processes RefSeq vertebrate proteins through a sequence analysis pipeline. The pipeline had .96 sensitivity, specificity, and Matthews Correlation Coefficient when tested using 372 vertebrate protein sequences with known secretion status (Klee and Ellis, 2005). The VSDB-analyzed RefSeq database can be compared to user-supplied sequences using VSDB BLAST or downloaded via VSDB Download. User-supplied sequences can be analyzed through the pipeline by using VSDB Analysis. More information on the software and methods is available here.
The site also contains sample output for VSDB pipeline analysis and VSDB Blast analysis. Usage and database statistics can be found here.