GREM1 may be a biological indicator and potential target of bladder cancer.

Gremlin 1 (GREM1) can regulate the development of many cancers. However, a few studies have revealed the role of GREM1 in bladder cancer (BC). To evaluate the expression and potential function of GREM1 in bladder cancer, we used R version 3.6.3 and related packages to analyze the data from common databases. Samples from our institution were assessed by immunohistochemical staining (IHC), which was approved by the Institutional Ethics Committee (K20220830). GREM1 was highly expressed in BC tissues according to the TCGA and IHC data. Data from TCGA, GSE31684, GSE32894, and IHC showed that GREM1 has significant prognostic value for BC patients. GREM1 is involved in immune and metabolism-related pathways. According to the TIDE algorithm, 61.0% of patients with low GREM1 expression responded well to immunotherapy, compared to only 13.3% in the high GREM1 expression group. High GREM1 expression was associated with sensitivity to cisplatin, docetaxel, gemcitabine, and vinblastine. Thus, GREM1 can predict prognosis and responses to immunotherapy and chemotherapy in BC patients, making it a potential biomarker and therapeutic target.