Previous studies on TROP2 expression in PC and CC have demonstrated that the overexpression of TROP2 was detected in 55% of 197 PC specimens and 61% of 70 CC specimens.13, 14 In this study, high expression of TROP2 was detectable in 40% of PC samples and 46% of CC samples, fairly consistent with previous studies. Here, TACSTD2 is linked to pachyonychia congenita.