in relation to other ACPA. The reactivity of EAC sera (n = 228) with FN-Cit1035,1036 was compared with the presence of antibodies to other citrullinated peptides, which are derived from vimentin (1 to 16: STCitSVSSSSYCitCitMFGG and 59 to 74: VYATCitSSAVCitLCitSSVP), fibrinogen (α-fibrinogen 27 to 43: FLAEGGGVCitGPRVVERH; β-fibrinogen 36 to 52: NEEGFFSACitGHRPLDKK) and α-enolase (5 to 20: KIHACitEIFDSCitGNPTV) . A. Fraction of patients recognizing 0 to 6 citrullinated peptides. B. Heat map showing the presence of antibodies to the citrullinated peptides obtained by an unsupervised cluster analysis. Red and green mark positive and negative sera, respectively. Missing values are depicted in grey.