CD22 and non-Hodgkin lymphoma: The anti-CD22 IT HB22.7/saporin-S6 exhibited strong cytotoxicity in NHL cell lines showing IC50 values in 10 pM range and completely prevented tumor development in athymic nude mice when the treatment was started within 24 hours from tumor inoculation, whereas the mixture of free HB22.7 and saporin-S6 did not exert cytotoxicity [83].