Photosensitivity, one of the major symptoms of SLE, has been proposed to occur as a consequence of antibody-dependent keratinocyte damage following the binding of antibodies to SS-A/Ro, SS-B/La, and U1 ribonucleoprotein (U1RNP) antigens expressed on the surfaces of UV-irradiated human keratinocytes [41]. This evidence concerns the gene RO60 and systemic lupus erythematosus.