UAS sequences regulate expression of a mutated form of 'λ-Egfr' (amino acid replacements Y1357F, Y1405F and Y1406F have been introduced into the Egfr intracellular domain). FlyBase curator comment: 'λ-Egfr' consists of the dimerization domain of the bacteriophage λ cI repressor (included to induce constitutive dimerization of the encoded protein), transmembrane sequence (from btl) and the intracellular domain of Egfr.