Diagnosis of lupus lesions in patients with skin rashes is determined by a clinical test using direct immunofluorescence (DIF) to detect immunoreactants, most commonly immunoglobulin G (IgG), IgM, IgA, and complement component 3 (C3), along the dermal-epidermal junction [2]–[4]. Here, CD40LG is linked to systemic lupus erythematosus.