The uppermost interest of investigating this question with P140 originates from the fact that this peptide, a 21-mer fragment of the 70 kDa spliceosomal small nuclear ribonucleoprotein (SNRNP70/U1-70K) protein, is a potent immunomodulator of lupus disease as shown in lupus-prone MRL/lpr mice18,19 and autoimmune patients with systemic lupus erythematosus20. Here, SNRNP70 is linked to systemic lupus erythematosus.