Secreted expression is important for proper formation of disulphide bonds, glycosylation, etc., and is the first step in the sorting of proteins to the ER, Golgi, transport vesicles, the vacuole, peroxisomes etc. The default pathway is secretion out of the cell into the cell wall and apoplast. Various sorting and retention signals determine the actual protein destination (see ImpactVector1.3). The vector can be used to change the targeting of the mature part of a protein to a secreted destination. The signal peptide used in this construct was derived from sea anemone equistatin (Outchkourov et al. 2003 Planta: 216: 1003; Outchkourov et al. 2003 Plant Physiology 133: 379).