In one study, a Tat-ELP-GFLG-Dox polypeptide consisting of a Tat peptide fused at the N-terminal, ELP, a tetrapeptide linker (GFLG) which was used to release its drug following cell entry and at the C-terminal a thiol reactive derivative of doxorubicin WP936, was able to overcome the efflux pumps in MES-SA/Dx5 and NCI/ADR-RES human uterine sarcoma cells [85]. The gene discussed is TAT; the disease is uterine corpus sarcoma.