MAPT and Alzheimer disease: As shown in Fig. 5b, AD model flies (elav-Gal4C155/+;+/+;UAS-Aβ42E693G/+ and elav-Gal4C155/+;+/+;UAS-APP.C99-UAS-MAPT/+) showed strong fluorescence of DCF, suggesting higher cellular ROS production (Fig. 5b).