ScerGAL4^NP2211 is expressed within the tracheal system, specifically by larval tracheal cells along which progenitors migrate. The expression pattern is dynamic and precise, almost perfectly matching the positions and timing of progenitor migration. In L3 animals, when progenitors are observed along the transverse connective (TC) branches, ScerGAL4^NP2211 is expressed in TC larval cells in tracheal metameres Tr4 and Tr5, but not in other metameres. Shortly after puparium formation, when pupal abdominal tracheae (PAT) progenitors turn to migrate toward the posterior, larval cells in the segment just posterior to PAT progenitors express ScerGAL4^NP2211. As progenitors continue along the dorsal trunk, larval cells in the dorsal trunk activate ScerGAL4^NP2211 expression one segment at a time from anterior to posterior, matching progenitor movement.

ScerGAL4^NP2211 drives expression in a subpopulation of larval glial cells.