The enhancer trap expression pattern coincides with the pattern observed for Gsc. Expression is first detected in a horseshoe pattern in the procephalic neurogenic region. Later these cells delaminate in two groups and form a ventro-lateral sector of each brain hemisphere. At stage 10, a new expression domain appears in the foregut anlage and shortly after marks the stomodeum. This expression domain gives rise to a specific region of the foregut at the junction of the pharynx and esophagus, a part of the stomatogastric nervous system, and a part of the ring gland.

In wandering third instar larva, no detectable β-gal staining.