IFN-β at doses of 50, 500, and 5000 U/mL failed to induce HLA-DR antigen expression in A431 human squamous cell carcinoma cells after a 24 hr incubation, whereas a similar treatment with IFN-γ significantly enhanced HLA-DR expression in a dose-dependant manner. This evidence concerns the gene IFNB1 and squamous cell carcinoma.