In mid instar larvae salivary glands levels are low during puff stage 1 and increase during puff stage 2 to become the predominant form in stage 3. Levels reach maximum in late larvae during puff stages 8-10, decreasing abruptly at stage 11. This expression pattern is also seen in Malpighian tubules and wing disk. Levels at puff stage 11 are appreciable in the gut and fat body. Transcripts are detected again in salivary glands from puff stages 12-14 and 17-21. The expression of this protein is developmentally regulated and is correlated with the 20-OH-ecdysone induced activity of puff 74EF. Belongs to the ETS family.