U1 and systemic sclerosis: Today, at least 10 SSc‐associated autoantibodies‐anticentromere (ACA), anti‐Scl70 (anti‐topoisomerase I), anti‐RNA polymerase III (anti‐RNAPIII), anti‐U3 ribonucleoprotein (anti‐RNP), anti‐Th/To, anti‐U11/U12 RNP, anti‐PM/Scl, anti‐Ku, anti‐RuvBL1/2, anti‐U1 RNP antibodies (ab)‐ have been reported in SSc patients.3, 4, 5