NAMPT and inflammatory skin disease: The altered expression of genes encoding key enzymes involved in NAD+ and PAR metabolism in psoriasis lesional skin, and in particular the robust induction of NAMPT, the accumulation of PAR and the nuclear translocation of AIFM1 in psoriasis lesional skin, point to NAMPT, PARP1, and AIFM1 as novel therapeutic targets to treat psoriasis and probably other skin inflammatory disorders.