ISG15 and neoplasm: To explore the immunomodulatory role of ISG15 in the tumor microenvironment, we conducted a comprehensive analysis of the ISG15 gene in 33 different tumors based on data from TCGA, GEO, and cohort data from Zhongshan Hospital affiliated with Fudan University and Nanjing Drum Tower Hospital affiliated with Nanjing Medical University, with regard to patient prognosis impact and immunorelevance.