https://www.selleckchem.com/products/arry-382.html Pilomatricoma, a benign skin appendage tumor, also known as calcifying epithelioma, consists of islands of epithelial cells histologically that contain anucleated cells in the center surrounded by basophilic cells and partial calcification. Sporadic pilomatricomas commonly have somatic mutations in the gene CTNNB1, but causative genes from germline and the underlying pathophysiology are unclear. In this study, we identified a germline missense variant of PLCD1 encoding PLCδ1, c.1186G>A (p.Glu396Lys), in a large Chinese family with autosomal dominant multiple pilomatricomas. Phospholipase C, a key enzyme playing critical roles in intracellular signal transduction, is essential for epidermal barrier integrity. The p.Glu396Lys variant increased the enzymatic activity of PLCδ1, leading to protein kinase C/protein kinase D/extracellular signal-regulated kinase1/2 pathway activation and TPRV6 channel closure, which not only resulted in excessive proliferation of keratinocytes in vitro and in vivo but also induced local accumulation of calcium in the pilomatricoma-like tumor that developed spontaneously in the skin of Plcd1E396K/E396K mice. Our results implicate this p.Glu396Lys variant of PLCD1 from germline leading to gain-of-function of PLCδ1 as a causative genetic defect in familial multiple pilomatricomas.We have previously shown that gain-of-function variations in transient receptor potential vanilloid-3 (TRPV3) underlay Olmsted syndrome, a rare hyperkeratotic skin channelopathy. In this study, we attempt to establish a genotype‒phenotype correlation in Olmsted syndrome, which has been unclear owing to the rarity and heterogeneity of the condition. We identified five previously unreported TRPV3 variations (R416Q, R416W, L655P, W692S, and L694P) and three recurrent variations (G568D, G568V, and L673F) in nine unrelated patients. Seven variants were expressed in human embryonic kidney 293 cells, and channel behavior wa