Support for this comes from work by Shiraishi et al.[70] (1986) demonstrating that chloroquine partially reversed the resistance of multi-drug-resistant KB carcinoma cells to the P-gp substrates adriamycin, daunomycin, vincristine, vinblastine and actinomycin D. Furthermore, it has been shown that P-gp inhibitors valspodar and elacridar or silencing P-gp with siRNA reversed lysosomal sequestration of doxorubicin, leading to its redistribution to its intended target, the nucleus[68]. Here, PGP is linked to carcinoma.