IL31RA and poikiloderma with neutropenia: Binding of IL-31 to its heterodimeric receptor leads to activation of the Janus kinase–signal transducer and activator of transcription (STAT) pathways that affect inflammation, pruritus, epidermal differentiation, and fibrosis.9 In addition to dorsal root ganglions, IL-31RA is expressed by a variety of inflammatory and structural cells, including myeloid cells, granulocytes, and keratinocytes.21 A recent immunofluorescence analysis revealed that most IL-31RA–expressing dermal cells in PN lesions were mast cells and macrophages.22