TGFB1 and pachyonychia congenita: The demonstration of a “mesenchymal-like” subset of GC-PC, expressing epithelial to mesenchymal transition (EMT) phenotype and morphology with high expression of the checkpoint protein TIM-3 and its ligand (galectin-9), as well as TGF-β, reinforces the concept of immune evasion and tumor EMT as central features of GC-PC [38,39].