MUC16 and pachyonychia congenita: The expression levels of ch5E6 epitope were directly correlated with the stages of disease progression from stage IA to stage III PC patients with a specific membrane/cytoplasmic MUC16 staining (N vs. IA; P = 0.0099, N vs IB; P = 0.0004, N vs IIA; P < 0.0001, N vs IIB; P = 0.0013, N vs III; P < 0.0001) (Fig. 1g).