The PTMs found in patients with SLE include phosphorylation, methylation, acetylation, isoaspartylation, etc. The proteins susceptible to phosphorylation in SLE are U1 small nuclear ribonucleoprotein (snRNP) 68K [83], SSA/Ro and SSB/La [84,85], spliceosomal Sm protein that is vulnerable to methylation in D1 and D3 subunits [86,87], the frequently ubiquitinated proteinase serine/arginine-rich splicing factor 1 (SKSF1) [88] and myeloperoxidase (MPO) [89,90]. The gene discussed is MPO; the disease is systemic lupus erythematosus.