Effect of D2C7-(scdsFv)-PE38KDEL on 43 and NR6M intracranial tumors in NSG mice. Male NSG mice (≈ 30 g; 8–12 weeks) bearing 43 (a) or NR6M (b) tumors were randomized into four groups, Sham, 0.2% PBS/HSA, P588-(scdsFv)-PE38KDEL, and D2C7-(scdsFv)-PE38KDEL. The test mice were treated over a three (43 xenograft) or seven (NR6M) day period with a total of 1 μg of D2C7-(scdsFv)-PE38KDEL diluted in 100 μl 0.2% PBS-HSA. Control mice were either left untreated (Sham) or treated with 0.2% PBS-HSA or 1 μg of the control immunotoxin, P588-(scdsFv)-PE38KDEL, diluted in 100 μl 0.2% PBS-HSA.