Nowadays great progress has been made in targeted therapy and comprehensive therapy for a few cancers. But the prognosis of the vast majority of cancer patients is still weakness. It has been proven that inflammation can affect the development and treatment of cancer. Some previous studies have suggested that inflammation-related interleukins (ILs) play a significant role in the development of some cancers. ILs act as a considerable role in immunity, and inflammation affects the development of cancer. Therefore, the expression profile of IL gene may also be one of the vital markers of early pathological changes, occurrence and progression of cancer. Currently, studies on the expression of IL27 in cancer are still extremely limited. Our work comprehensively and systematically studied the IL27 gene expression in the generic cancer when compared with the existing IL27 gene related research experiment. We screened out cancer species linked with poor prognosis, and explored the correlation between IL27 gene expression and immune cell infiltration and immune microenvironment in these cancers further, providing an increasing number of the direct basis for subsequent studies. Our findings showed that IL27 can be used to assess prognosis and immune infiltration in patients with colon adenocarcinoma (COAD), glioblastoma multiforme (GBM), head and neck squamous cell carcinoma (HNSC), skin cutaneous melanoma (SKCM) and testicular germ cell tumors (TGCT) as a biomarker.