GAS6 and cancer: To further confirm that neutrophils are indeed a major source of Gas6 expression in human liver metastases after chemotherapy treatment, we enzymatically disaggregated fresh liver samples from chemotherapy-treated patients with CRC into single cell suspensions and isolated neutrophils, macrophages, fibroblasts and cancer cells by flow cytometry-based cell sorting (figure 8E; online supplemental figure S9K).