PGP and breast cancer: It was reported that in the KB cell line, human breast cancer MCF-7 cell line, and their corresponding P-gp overexpressing cell lines KBv200 and MCF-7/ADR, neither upregulation nor downregulation of survivin could affect P-gp expression on protein level[34], but the PI3k/Akt pathway was found to be involved in P-gp associated survivin transcription activity and affected the expression of both P-gp and survivin in the same pattern in MCF-7/ADR[36].