KRT6B and pachyonychia congenita: PC was formerly divided into two subtypes: PC-1, also known as Jadassohn–Lewandowsky syndrome, which is associated with variants in KRT6A and KRT16, and PC-2, also known as Jackson–Lawler syndrome, which was linked to variants in KRT6B and KRT17. Nevertheless, due to observed similarities in molecular and clinical data between these subtypes, a molecular analysis–based classification was adopted [3, 4].