BDNF and neoplasm: Notably, both TSPAN7- and BDNF-reactive IgA: (1) antagonized tumour growth in vivo more effectively than did irrelevant IgA (Fig. 3d); (2) induced areas of central necrosis and TUNEL+ cells (Fig. 3e, Extended Data Fig. 5h–j); and (3) was engulfed by tumour cells more effectively than was irrelevant IgA (Extended Data Fig. 5k).