CTHRC1 and pachyonychia congenita: High CTHRC1 expression correlates with increased levels of immune checkpoints PD-1 and PD-L1, enhanced infiltration of immune cells such as B cells, CD4+ T cells, macrophages, neutrophils, and dendritic cells, and is associated with genes like MMP9, MUC1, and SLC2B1 that drive PC progression.