Previous mosaicism studies in paediatric patients with NLRP3 mosaicism showed presence of the mosaic mutation in comparable levels both in the myeloid and lymphoid lineages as well as affecting cells from ectodermic origin (3, 7, 10), unlike what has been described in adult late-onset CAPS patients (11–13). Here, NLRP3 is linked to cryopyrin-associated periodic syndrome.