BACKGROUND: Head and neck squamous cell carcinomas (HNSCs) are a diverse collection of tumors that originate in the oral cavity, pharynx, and larynx and pose a severe threat to human health, contributing to a fast-rising burden of cancer morbidity and mortality. The search for prognostic biomarkers of HNSC has been a hot topic. Spindle and kinetochore-associated () complex, including three members , which stabilize the spindle microtubules at the kinetosite during mitosis metaphase, has been demonstrated to be associated with poor prognosis of different cancers. The function of in HNSC remains to be investigated. We used a vast variety of public datasets and web-based technologies to investigate complex expression and its link to patient prognosis, and discovered multiple pathways by which the complex is regulated in HNSC. METHODS: The Cancer Genome Atlas (TCGA) database was used to determine expression level in HNSC. -related proteins level and immune cells infiltration level were identified. Metascape was used for Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. GSE31056 from Gene Expression Omnibus (GEO) database was used as an external dataset for data validation. A nomogram containing for the prognosis of HNSC patients was established. RESULTS: were highly expressed in HNSC. High expression of was significantly related to the poor overall survival (OS) and poor disease-free survival (DFS) of HNSC patients. and the related proteins were enriched in cell division, chromosome segregation, and mitotic cell cycle. expression was obviously positively correlated to several immune cells' infiltration. The expression values of were higher in tumors than in healthy tissues in GSE31056. CONCLUSIONS: were shown to be related to the prognosis and immune cell infiltration of HNSC, which could be used as biological markers and therapeutic targets for HNSC.