At present, it is known that free IL-18 in the serum is a poor prognostic marker for PC patients, and studies have speculated that IL-18 has a dual effect on tumor cells: to promote growth and expansion of PC cells by activation of the NF-κB signaling pathway, and to inhibit PC growth through activation of the anti-tumor immune response [38,39]. The gene discussed is IL18; the disease is pachyonychia congenita.