CXCR4 and systemic lupus erythematosus: Some studies pioneered this field to some extent and notably pointed out the importance of the CXCL12/CXCR4 pathway in systemic lupus erythematosus (SLE) physiopathology (Henneken et al., 2005; Chong and Mohan, 2009; Zhao et al., 2017; Barrera-Vargas et al., 2018).