Furthermore, we distinguished intermetastatic Th1 CD4+ T cell function, which in PC is predominantly governed by immunosuppressive PD-L1 signaling toward CD8+ cells and accompanied by a loss of B cell–dependent MHC-II signaling, potentially resembling a disturbed antigen-presenting function of MHC-II+ B cells in PC. This evidence concerns the gene CD4 and pachyonychia congenita.