Feng Y, et al. - Researchers examined the link between differential expression microRNAs (miRNAs) [DEmiRNAs] and muscle-invasive bladder urothelial carcinoma (MIBC) survival, using adaptive lasso Cox’s proportional hazards model. By examining epithelial-mesenchymal transition (EMT) signature genes and TIMER database, the assessment of the EMT score and immune infiltration abundance, respectively, was done. Employing the lasso Cox algorithm, 8 DEmiRNAs were found to be related to the survival rate of MIBC. A calculated marker was developed via the linear integration of these 8 DEmiRNAs which could be applied to differentiate the prognosis risk in both the Cancer Genome Atlas (TCGA) dataset and independent validation dataset. For the AUC in the TCGA dataset and validation dataset, being 0.73 and 0.63, respectively, reasonably high predictive values were yielded by the constructed marker. The expression values of let-7c, miR-100, and miR-145 were found to be related to EMT score and the abundance of macrophage in tumor tissue as well. Overall, the prognostic risk of MIBC could be significantly predicted by this novel risk score signature based on the combination of 8 miRNAs. In addition, it might offer insight into immunotherapy and targeted treatment of MIBC.