PE and its fragments have been fused to anti-GPC3 (158, 159), anti-GPC2 (110), anti-VEGFR2 (160), anti-CD7 (161, 162), anti-HER2 (163), and anti-CD38 (164) nanobodies, enhancing cytotoxic effects in various tumor models. Here, ERBB2 is linked to neoplasm.