FBL and systemic sclerosis: Several autoantibodies, including anti-topoisomerase I (topo I), -centromere (ACA), -RNA polymerase III (RNAP III), -U3RNP/fibrillarin, and -Th/To, have been reported to be associated with scleroderma (systemic sclerosis, SSc); some are considered highly specific disease markers while others are considered relatively specific [2].