In PC, it was also demonstrated that miR-21 enhances endothelial growth factor (EGF)-induced proliferation via targeting of SPRY2 and activating the MAPK/ERK and phosphatidylinositol 3-kinase (PI3K)/AKT signaling pathways [41], revealing a novel potential therapeutic target for patients with PC. Here, AKT1 is linked to pachyonychia congenita.