Several studies have revealed these shared genetics through simple comparisons of the associated genes [68], as was the case in a study conducted by our group, where González-Serna et al. [69] considered the association of a rare variant in the TNFSF13B gene with RA and replicated this association in systemic lupus erythematosus (SLE) patients. The gene discussed is TNFSF13B; the disease is systemic lupus erythematosus.