An acquired CAPS-like disorder known as Schnitzler syndrome can very rarely develop in patients with low grade lymphoplasmacytic lymphoma, characterized by the presence of an IgM paraprotein and, intriguingly, myeloid-restricted somatic NLRP3 mosaicism has been reported in two patients who had been diagnosed to have Schnitzler syndrome (15). Here, CD40LG is linked to Schnitzler syndrome.