GAST and pachyonychia congenita: Osborne et al. recently demonstrated that the tumor vaccine polyclonal antibody stimulator (PAS), which selectively targets gastrin, induces system to produce specific polyclonal anti-gastrin antibodies and then decrease PC growth and metastases by downregulating dense desmoplastic fibrosis in the TME, inducing T cell activation, and altering the TME to make it more responsive to immunotherapy with a PD-1 immune checkpoint antibody [45].