PTPRC and systemic lupus erythematosus: Enriched functions within this signature included pathways linked to cell metabolism, innate immune system and neutrophil degranulation (online supplemental figure S1C, table S1B), reiterating the role of neutrophils in lupus kidney injury.32 By representing the signature DEGs as a gene network, we found several hub genes with high-degree nodes of the network corresponding to human lupus-susceptibility loci33–35 such as FCGR2B, PTPRC, ITGAM, NCF1 and RASGRP1 (online supplemental figure S1D, table S1C).