The loss of STS activity due to STS gene deletion or point mutations results in X-linked ichthyosis, a genetic skin disorder that affects 1 in 2000 to 1 in 6000 males and is characterized by typical scaling of the skin epidermis (Gelmetti and Ruggero, 2002). The gene discussed is STS; the disease is syndromic recessive X-linked ichthyosis.