Taken together, these findings show that (1) the infiltration of neutrophils in metastatic lesions after chemotherapeutic treatment leads to metastatic relapse in vivo, (2) Gas6 expression is highly upregulated in neutrophils after chemotherapy and (3) Gas6 promotes regrowth of gemcitabine-treated pancreatic cancer cells. Here, GAS6 is linked to familial pancreatic carcinoma.