CLK1 and systemic sclerosis: Using ProtoArray® method, we first defined 6 out of 9483 spotted human proteins specifically recognized by IgG autoantibodies from 20 sera of patients with SSc: Fibroblast Growth Factor 2 (FGF2), Allograft Inflammatory Factor 1 transcript variant 1 (AIF1), Ephrin Type-B receptor 2 (EphB2), Dual specificity protein kinase CLK1 (CLK1), Three prime Histone mRNA EXonuclease 1 (THEX1) and Ankyrin repeat and Sterile alpha motif domain containing 6 (ANKS6).