HPGD and skin aging: Hence, we calculated their Cutoff value, and the results showed that when AR, HPGD and PI3 expression were up-regulated to 8.221, 9.686 and 7.603 respectively, BCEH and CXCR2 expression were down-regulated to 9.948 and 7.695 respectively, they could be applied as a criterion for diagnosing skin aging.