TRIM21 and systemic lupus erythematosus: In contrast, however, Ro52γ is targeted both at Ro52Ex4 and the C-terminal domain, offering it an alternative self-antigen to explain the subsets of anti-Ro52 antibodies found in SLE — i.e., anti-Ro52Nt, anti-Ro52Ex4, and anti-Ro52γCT — as well as the limited humoral response against C-terminal Ro52α.