In a mouse model of squamous carcinoma, CD20+ B-lymphocytes affect tumour growth and decrease response to chemotherapy by altering a macrophage dependent T-cell response.9 In line with this, targeting of B-cells in a mouse model of pancreatic cancer modulated macrophage function, restored tumour killing by T-cells and improved the response to chemotherapy.10 Here, MS4A1 is linked to familial pancreatic carcinoma.