FCRL5 and systemic lupus erythematosus: The use of the SLE-ANA-panel was additionally supported by the observed expansion of atypical memory B cells (AtMs, IGHD−CD27−CD11c+FCRL5+ [defined in Figure S2A]) in both COVID-19 and SLE patients (Oliviero et al., 2020; Su et al., 2020).