It will focus on the WRN (RecQ Protein-Like 2, RECQL2; MIM*604611 [1]) helicase and the FAM111B (Family with Sequence Similarity 111, Member B; MIM*615584 [1]) serine protease, responsible—when mutated—for Werner (WS; MIM#277700 [1]) and Hereditary Fibrosing Poikiloderma (POIKTMP; MIM#615704 [1]) syndromes, both exhibiting a clinical overlap with RTS and NUP98 nucleoporopathy. The gene discussed is FAM111B; the disease is Werner syndrome.