TRIM21 and systemic lupus erythematosus: In line with these observations, our results from cross-admixture experiments had also indicated that the occurrence of specific anti-nuclear antibodies in the sera of SLE (anti-histones) and SS patients (anti-Ro/SSA) is associated with failure to support the ApoCell-phagocytosis by healthy monocytes, whereas we have found increased IgG binding activity to early apoptotic cells among anti-Ro/SSA-positive sera.