Recently, Ribosome-Inactivating Proteins (RIPs) as a class of anticancer medicines have garnered considerable attention due to their novel anticancer mechanism. Although the medications are small, RIPs utilize the Large-Size Effect (LSE) to block the efflux procedure that are regulated through Drug Resistance Transporters (DRTs), and protect host cells from drug transfection. There are many significant challenges for their therapeutic applications that seriously restrict their usefulness, particularly their strategy towards tumor cells. The primary objective of this review is to emphasize Trichosanthin (TCS) along with Gelonin (Gel) and additional types of RIPs, particularly scorpion venom-derived RIPs, to demonstrate that they should be grappling through what kinds of bio-barriers to overcome in cancer therapeutic science. Next, we will emphasize the latest state-of-the-art in providing cancer treatment RIPs.