GAS6 and metastatic malignant neoplasm: In line with our previous colony formation experiments, we found an increase in proliferating metastatic cancer cells (MUC1+Ki67+) in gemcitabine treated PCLS cultures supplemented with recombinant Gas6 compared with gemcitabine treated PCLS cultures lacking recombinant Gas6 (figure 5F, G; online supplemental figure S6E, F).