PCNA and scleroderma: These include immunoglobulin class IgG to different antigens, namely, Smith (Sm) antigen, ribonucleoprotein (RNP) 70, Sjogren’s syndrome type A (SSA), recombinant Ro52 (Ro52), Sjogren’s syndrome type B (SSB), scleroderma/topoisomerase (Scl-70), histidyl-tRNA (Jo-1), anticentromere (CB), histones (his), proliferating cell nuclear antigen (PCNA), double-stranded DNA (dsDNA), nucleosomes (Nuc), ribosomal protein (Rib), anti-mitochondrial (M2) antibody, and polymyositis/scleroderma (PM-Scl).