Conversely, following treatment of PBMCs from quiescent SLE patients with a-amanitin, an inhibitor of RNA polymerase II, which causes conversion of chromatin into a more condensed form [16], chromatin compaction of the N-ras gene locus (Additional file 1: Figure S1a, b) was accompanied by reduction of the efficiency of nucleotide excision repair and increased DNA damage burden (Additional file 1: Figure S1c, d). This evidence concerns the gene NRAS and systemic lupus erythematosus.