With the exception of TROP2, all proven or putative markers of SCs (ALDH1A1, NANOG, SOX2, OCT4, KLF4, EGR1, BMI1, LGR5, LGR6, LRIG1, TSPAN7, and TSPAN13) were expressed in LNs from control patients to similar or even higher levels than in PC patients (Fig. 2). The gene discussed is KLF4; the disease is pachyonychia congenita.