Given that CELF2 expression was significantly correlated with diverse levels of immune infiltration in most of cancer types and combined with the results of CELF2 expression and prognostic analysis in pan‐cancer, we selected subjects by setting the following criteria: (1) CELF2 was significantly up‐ or down‐regulated in Oncomine and TIMER database at the same time; (2) CELF2 had a consistent prognostic value in PrognoScan and Kaplan‐Meier plotter database; (3) CELF2 expression was negatively associated with tumour purity and correlated with more than two TIIC levels. The gene discussed is CELF2; the disease is neoplasm.