C3 and systemic lupus erythematosus: Further links of C3-LHF1 to Lupus and particularly lupus nephritis also come with its physical association in plasma to peroxidasin (Appendix Fig. S3C), a protein suggested to be an autoepitope in lupus nephritis (Manral et al, 2019), or lupus-linked proteins such as RPL22 (Kegerreis et al, 2019), and WDR1 (Kile et al, 2007).