The strong synergistic action of certain ecdysteroids with one or more of the above-mentioned chemotherapeutics was confirmed on a broad range of cancer cell lines of various origin, including human breast (MCF-7 and its sub-cell line MCF-7Dox adapted to doxorubicin), prostate (PC3, LNCaP), epidermal (KB-3-1 and its sub-cell line KB-C-1 adapted to colchicine), and neuroblastoma (SH-SY5Y), as well as two murine lymphoma cell lines (L5178 and its sub-cell line L5178MDR transfected to express the human ABCB1 transporter, commonly referred to as P-glycoprotein or P-gp) [4,5,6,7,8]. Here, PGP is linked to cancer.