Objective To investigate the expression level, clinical significance, and prognostic value of chaperonin containing t-complex 1 subunit 7 (CCT7) in lung adenocarcinoma (LUAD).Methods1. The UALCAN and TCGA databases were used to analyze the differential expression of CCT7 mRNA in LUAD, its clinicopathological correlations, and prognostic value. Gene set enrichment analysis was performed to explore the potential mechanisms of CCT7 mRNA in LUAD. Immune infiltration analysis was conducted to assess the level of immune cell infiltration associated with CCT7 mRNA, and the GEPIA database was used to analyze its correlation with immune checkpoint molecules. 2. Immunohistochemistry was used to detect CCT7 protein expression in 122 LUAD tissues and 75 adjacent non-cancerous tissues, and its relationships with clinicopathological features and prognosis were analyzed.Results1. Bioinformatics analysis showed that CCT7 mRNA was significantly overexpressed in LUAD tissues (P<0.001). Its expression level was correlated with sex, TNM stage, T stage, lymph node metastasis, distant metastasis, and survival status (all P<0.05). Survival analysis indicated that high CCT7 expression was associated with poor prognosis in LUAD patients (P<0.05) and was an independent risk factor for overall survival. Gene set enrichment analysis revealed that the CCT7 mRNA high-expression group was enriched in pathways including purine/pyrimidine metabolism and nucleotide excision repair. Immune infiltration analysis suggested that CCT7 mRNA expression was correlated with the infiltration of immune cells such as activated CD4+ memory T cells and plasma cells (all P<0.05), and showed a weak negative correlation with cytotoxic T-lymphocyte associated antigen 4 (CTLA-4) (r = ?0.12, P<0.05). 2. Immunohistochemistry confirmed that CCT7 was highly expressed in LUAD tissues (P<0.001). Its expression was correlated with age, TNM stage, T stage, lymph node metastasis, distant metastasis, and survival status (all P<0.05). Survival analysis showed that high CCT7 expression predicted poor prognosis in LUAD patients (P<0.05) and was an independent risk factor. The prognostic model incorporating CCT7 demonstrated good predictive performance.ConclusionsCCT7 is highly expressed in LUAD and is closely associated with poor patient prognosis. It may promote tumor progression by regulating cell cycle-related pathways and mediating humoral immunity, thus representing a potential prognostic marker and therapeutic target for LUAD.