T5

**T5 is an ambiguous research-compound identifier, not a uniquely resolvable drug name.** It has been used for at least two distinct preclinical anticancer small molecules. One T5 is a carbohydrate-conjugated naphthalene-diimide G-quadruplex ligand studied in colorectal cancer; it binds ribosomal-DNA G-quadruplexes, impairs RNA polymerase I elongation, suppresses ribosomal RNA transcription, disrupts nucleoli, promotes proteasome-dependent degradation of RNA polymerase I catalytic subunit A, and induces autophagy. A separate T5 is a 2-aminopyrimidine ponatinib derivative evaluated in chronic myeloid leukemia cell lines, including imatinib-resistant models, as a candidate BCR-ABL1 tyrosine kinase inhibitor. These are different chemical entities and must not be merged.