This novel partner cell line is a tri-hybrid of IL-4 secreting Th2 lymphoblast derived from a patient with acute lymphoblastic leukaemia (T), CD20+ B lymphoblast, also derived from a patient with acute lymphoblastic leukaemia (W), and IL-6 secreting peripheral blood-derived CD14+ monocyte (M). This evidence concerns the gene IL4 and acute lymphoblastic leukemia.