Thus, in the presence of the more common autoantibodies (such as to Ku, synthetases, U1RNP, fibrillarin, PM-Scl, or SSc autoantigens), at least one more autoantibody was present in the majority (mean 78.5%, range 60% to 93%) of sera (Table 2). This evidence concerns the gene FBL and systemic sclerosis.