In cases of familial PLCA, pathogenic heterozygous missense mutations have been mapped to the OSMR gene encoding the interleukin-31 (IL-31) receptor subunit oncostatin-M receptor ß (OSMRß), and the IL31RA gene encoding the IL-31 receptor alpha, which pairs with OSMRß to form the IL-31 receptor [18,19,20,21]. The gene discussed is IL31; the disease is primary cutaneous amyloidosis.