{"entity":{"id":"ttk","kind":"target","name":"MPS1 (TTK)","aka":["MPS1","Mps1","TTK protein kinase","PYT","CT96"],"tldr":"MPS1 arms the checkpoint that holds a dividing cell until its chromosomes are attached. Blocking it lets cancer cells divide carelessly and die; one inhibitor is in phase 1/2 in breast cancer.","summary":"TTK (chromosome 6q14.1) encodes the dual-specificity kinase MPS1, which is involved in mitotic spindle assembly checkpoint signalling, delaying anaphase until chromosomes are bioriented, and in the repair of incorrect kinetochore-microtubule attachments; it phosphorylates MAD1L1 to promote the checkpoint and is present in rapidly proliferating cell lines (UniProt P33981). CFI-402257, a TTK inhibitor, is in phase 1/2 alone, with fulvestrant, and with paclitaxel in HER2-negative breast cancer (NCT05251714, NCT03568422).","asOf":"2026-09-24","links":[{"label":"HGNC HGNC:12401","url":"https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:12401"},{"label":"UniProt P33981","url":"https://www.uniprot.org/uniprotkb/P33981/entry"},{"label":"NCBI Gene 7272","url":"https://www.ncbi.nlm.nih.gov/gene/7272"},{"label":"ClinicalTrials.gov NCT05251714","url":"https://clinicaltrials.gov/study/NCT05251714"}],"tags":["checkpoint-map"],"related":["bub1","aurkb","aurka"],"cancers":["breast-hr-positive"],"sections":[],"technologies":[],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":["mitotic-spindle-checkpoint"],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":["Prevalence not recorded: HGNC and UniProt carry no positivity rates."],"provenance":{"editedBy":"OnCo checkpoint map (HGNC REST, UniProt REST, ClinicalTrials.gov v2)","editedOn":"2026-09-24"},"symbol":"TTK","role":[],"sources":[{"label":"HGNC HGNC:12401","url":"https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:12401","note":"approved symbol, name, aliases and cross-references"},{"label":"UniProt P33981","url":"https://www.uniprot.org/uniprotkb/P33981/entry","note":"protein name, function and tissue specificity"}],"specificitySources":[],"hgnc":"HGNC:12401","ensembl":"ENSG00000112742","uniprot":"P33981","entrez":"7272","biology":"The apex kinase of the spindle assembly checkpoint; inhibitors override the checkpoint rather than enforce it.","whereFound":["Rapidly proliferating cells (UniProt P33981)","Breast cancer trials of CFI-402257"],"targetClass":"kinase","prevalence":[]},"route":"/targets/ttk/","neighbours":{"target":[{"id":"aurka","kind":"target","name":"AURKA","route":"/targets/aurka/"},{"id":"aurkb","kind":"target","name":"AURKB","route":"/targets/aurkb/"},{"id":"bub1","kind":"target","name":"BUB1","route":"/targets/bub1/"}],"cancer":[{"id":"breast-hr-positive","kind":"cancer","name":"HR-positive / HER2-negative breast cancer","route":"/cancers/breast-hr-positive/"}],"pathway":[{"id":"mitotic-spindle-checkpoint","kind":"pathway","name":"Mitosis & the spindle assembly checkpoint","route":"/pathways/mitotic-spindle-checkpoint/"}],"term":[{"id":"checkpoint","kind":"term","name":"Checkpoint (two meanings)","route":"/terms/checkpoint/"}]}}