ObjectiveThis study aims to explore the role of CBLL1 in pan-carcinoma and tumor immune infiltrates. MethodsDownload mRNA expression, mutation and clinical data in UCSC database, to analyze the relationship between CBLL1 expression and clinicopathological vlaue, and immune microenvironment in pan-cancer. CIBERSORT was used to analyze the relationship between CBLL1 expression and the infiltration of pan-carcinoma immune cells. The mRNA expression data of UCSC database were used to analyze the correlation between CBLL1 expression and pan-cancer immunomodulations, checkpoints and receptor molecules. ResultsThe levels of CBLL1 mRNA expression in pan-cancer tissues were abnormal. The level of CBLL1 is related to the age, race, clinical stage and treatment effect of patients with pan-carcinoma and associated with the prognosis of patients with KIRC, LUSC, THCA, THYM, MESO, PRAD, STAD, and UVM. Univariate COX regression analysis showed that expression of CBLL1 was a risk factor for poor prognosis in patients with KICH, KIRC, LAML, THYM, KIRC, PCPG, OV, PRAD, STAD, GBM and UVM. The expression level of CBLL1 was correlated with BLCA, BRCA, COAD, LAML, LGG, LUAD, LUSC, SARC, STAD, THCA, THYM and UVM tumor mutational burden, and with ACC, BRCA, CESC, COAD, DLBC, HNSC, PRAD, READ, SARC, STAD, TGCT, THCA and UCEC microsatellite instability. The expression level of CBLL1 was correlated with cancer stromal cells and immune cells. The expression of CBLL1 is related to pan-cancer immunomodulators, checkpoints and receptor molecules. ConclusionCBLL1 is abnormally expressed in patients with pan-carcinoma, which is expected to be a biomarker for prognosis, mutation and immune infiltration in patients with pan-carcinoma.