Expression is most prevalent in third instar larvae in the middle midgut, which contains the copper cells, with lower expression in the flat cells and the iron cells. In larval and adult Malpighian tubules, expression is observed in the Type 1 (principle) cells and not in the Type II (stellate cells). In the adult midgut, expression is observed in the R2 and R3 compartments, with lower expression in the R1 compartment.