S100A2 and pachyonychia congenita: Furthermore, based on GSE28735 data set, our study demonstrated that the expression of eight among the eleven differentially expressed S100A family members in PC tissues was up‐regulated compared with those in the adjacent non‐tumour tissues, including S100A2, S100A4, S100A6, S100A10, S100A11, S100A13, S100A14 and S100A16 (Figure 2).