Intriguingly, in CeD patients, circulating gluten-specific CD4+ T cells with a unique cell surface signature (CD38+, CD39+, CXCR3+, PD-1+, ICOS+, CD161+, CCR5+ and CD28+) were observed to show a high resemblance to gluten-specific CD4+ T cells found in the affected small intestinal mucosa, but also to CD4+ T cells in patients with systemic lupus erythematosus [109]. This evidence concerns the gene CD4 and systemic lupus erythematosus.