COL4A4 and pachyonychia congenita: Among ECM-related genes, collagens (COL4A4, COL6A2, COL8A1, COL14A1), integrins (ITGA1, ITGA6, ITGA8, ITGA10, ITGAV, ITGB2, ITGB8), as well as MMP7, were mostly overexpressed in patients below 55 years old, rather than in the groups of 60–70 and above 70 years old at the early stage of PC, and the profile switched to the opposite with stage progression.