FATP4 gene is evolutionally conserved and is the only FATP known so far to cause severe neonatal abnormalities or death as reported in FATP4-null mice [76–79], as well as IPS patients with FATP4 mutations seen mainly in Europe [74,75,92–96] and some in Asia [97,98]. This evidence concerns the gene SLC27A4 and ichthyosis prematurity syndrome.