CD47 and lymphoma: Additionally, using E.G7-hCD47 cells (a mouse-derived T lymphoma cell line that stably expresses human CD47) as the target cells, BC31M4-F(ab′)2 alone or BC31M4-mIgG1 (a mouse isotype with weak Fc effector functions [38, 39]) also did not induce the phagocytosis of E.G7-hCD47, whereas BC31M4-mIgG2a (a mouse isotype with strong Fc effector functions [38, 39]) induced phagocytosis of E.G7-hCD47 cells (Additional file 1: Fig. S2b).