<qa>  How many male volunteers are randomized to receive topical application of ER4017?10 male volunteers aged from 60 to 75 years are randomized to receive topical application of ER4017 versus placebo on skin inner forearms twice a day during 3 months. After sequential selloptape strips, epidermal samples of treated and control skin are removed under local anesthesia, using a dermatome. Differential gene expression analysis is performed using micro array techniques and quantitative RT-PCR. 