TOP1 and systemic lupus erythematosus: The expression levels of 4 peptides, acidic ribosomal phosphoprotein (P0)-4, acidic ribosomal phosphoprotein (P0)-11, DNA topoisomerase 1 (full length)-1, and U1-SnRNP 68/70 KDa-1, were significantly different between the SLE patients and normal controls (Figure 2, Table 2).