POFUT1 and histiocytic sarcoma: Moreover, mutations in POFUT1 and POGLUT1 genes, encoding, respectively, for GDP-fucose protein O-fucosyltransferase 1 protein and protein O-glucosyltransferase 1, two proteins associated with Notch signaling, have been described in patients suffering with HS and Dowling–Degos disease, an autosomic dominant inherited skin disease that can occur alone or in association with HS in which patients present flexural hyperpigmentation [53].