BTG3 and systemic sclerosis: Approximately 10% of SSc patients are ANA-negative, but both ANA-negative and ANA-positive patients may present with novel antibodies, including anti-elF2B, an-ti-RuvBL1/2 complex, anti-U11/12 RNP, anti-U3RNP, anti-BICD2, anti-Ku and an-ti-PM/Scl [7,8,9,10,84,85,86,87,88,89,90,91].