Yu W, Zhu J, Han Y, et al. - In the present study, the researchers sought to examine the morphological and anatomical features of port-wine stains (PWSs) treated by pulsed dye laser (PDL) based on their location on the limb and suggest a possible explanation for the difference in PDL treatment efficacy. Compared with those positioned distally on the limb, PWSs positioned proximally on the limb often respond better to PDL treatment. Self-controlled case series aimed at evaluating the localization-based efficacy and anatomic characteristics of PWSs in response to PDL treatment have not been published before.