GFAP and familial pancreatic carcinoma: Instead of a continuous connection with nerves, Schwann cells, labeled with specific markers S100 and glial fibrillary acidic protein (GFAP), represent a “nerve-independent, stromally distributed” pattern in human pancreatic cancer and two commonly used PDAC transgenic mouse models, the KC mice (p48-Cre/LSL-KrasG12D) and KP mice (p48-Cre;LSL-KrasG12D;Trp53−/−) [7].