INK 128 (MLN0128) is a potent and selective inhibitor of mTOR (mammalian target of rapamycin), specifically targeting both mTORC1 and mTORC2 complexes. It is widely used in cancer research due to its ability to block signaling pathways involved in cell growth, proliferation, and survival. By inhibiting mTOR, INK 128 induces cell cycle arrest and promotes apoptosis in various tumor cell lines, including those resistant to conventional therapies. It has shown promising activity in preclinical models of hematologic malignancies such as multiple myeloma, leukemia, and lymphoma, as well as solid tumors like breast, prostate, and lung cancers. INK 128 is also investigated for overcoming resistance to other targeted therapies, especially in tumors with PI3K/AKT/mTOR pathway activation. Due to its oral bioavailability and favorable pharmacokinetic profile, it has advanced into clinical trials for evaluating efficacy and safety in cancer patients. Additionally, research explores its potential in combination therapies with chemotherapy, immunotherapy, or other kinase inhibitors to enhance antitumor effects.