The study investigates the expression of vascular permeability factor (VPF; also known as vascular endothelial growth factor) by epidermal keratinocytes during wound healing. The authors found that persistent microvascular hyperpermeability to plasma proteins, which is a characteristic of normal wound healing, is associated with the expression of VPF. They demonstrated that VPF mRNA was highly expressed by keratinocytes at the wound edges and later in the subepidermal granulation tissue as keratinocytes migrated to cover the wound surface. In situ hybridization revealed that keratinocytes and occasional mononuclear cells (probably macrophages) expressed VPF mRNA. Secreted VPF was detected in the medium from cultured human keratinocytes. These findings suggest that keratinocytes are an important source of VPF, which may play a crucial role in maintaining vascular hyperpermeability and promoting angiogenesis during wound healing.The study investigates the expression of vascular permeability factor (VPF; also known as vascular endothelial growth factor) by epidermal keratinocytes during wound healing. The authors found that persistent microvascular hyperpermeability to plasma proteins, which is a characteristic of normal wound healing, is associated with the expression of VPF. They demonstrated that VPF mRNA was highly expressed by keratinocytes at the wound edges and later in the subepidermal granulation tissue as keratinocytes migrated to cover the wound surface. In situ hybridization revealed that keratinocytes and occasional mononuclear cells (probably macrophages) expressed VPF mRNA. Secreted VPF was detected in the medium from cultured human keratinocytes. These findings suggest that keratinocytes are an important source of VPF, which may play a crucial role in maintaining vascular hyperpermeability and promoting angiogenesis during wound healing.