KCNQ1OT1 and pachyonychia congenita: In this study, we demonstrated that the KCNQ1OT1/miR-15a/PD-L1 axis essentially promoted the activation of Ras/ERK signaling, which was concomitant with their stimulation of other malignant phenotypes of PC, supporting that one mechanism responsible for the pro-tumor activities of KCNQ1OT1/miR-15a/PD-L1 axis was through the activation of Ras/ERK signaling.