PADI4 and cancer: To identify the cell types that produce PAD4 in the hepatic metastatic environment, we sorted cells from murine experimental liver metastases generated from three different human CRC cell lines into four groups: cancer cells expressing GFP, granulocytes (CD11b+Ly6Ghi), other myeloid cells (CD11b+Ly6Glo) and the remaining stromal cells (GFP−, CD11b−, Ly6G−) (Supplementary Fig. 6C).