The distal enhancer is modular and contains multiple functionally important sequences. Enhancer DE3 predominantly activated transcription in the
m3,
m4,
m5, and
m7 pharyngeal muscles, it also activated occasional expression in the pharyngeal-intestinal valve and body wall muscle cells. Two distinct sequences within DE3 are sufficient to enhance pharyngeal gene expression. The distal enhancer
de209 can activate transcription in the pharyngeal muscles, although it exhibits distinct patterns of activity in other cell types.