Exogenous wtp53 expression in JSQ-3 xenograft tumors after i.v. injection of TfRscFv-LipA2-p53. Athymic nude mice carrying JSQ-3 xenograft tumors were i.v. injected with either TfRscFv-LipA2-p53 or the unliganded LipA-p53. 48 hrs later the animals were euthanized, the tumor, liver and skin excised, and protein isolated for Western analysis. L = liver; T = tumor; S = skin; Arrow 1 = Endogenous p53; Arrow 2 = Exogenous wtp53. This experiment was repeated three times with representative results shown here. A high level of expression of the exogenous wtp53 protein is evident in the tumor from the mouse injected with the TfRscFv-LipA2-p53 immunolipoplex, while only limited expression of the exogenous p53 is observed in skin and only endogenous mouse p53 was evident in liver of the same mouse. In contrast, a much lower level of exogenous p53 expression was observed in the tumor from the mouse injected i.v. with the unliganded lipoplex, LipA-p53.