IL6 and cancer: Interestingly, a study based on the observation that human papillomavirus 16 (HPV16)-positive head and neck cancers are more sensitive to immunotherapy than HPV16- specimens found that IL-6 production by HPV16+ cancer cells specifically favors RT-induced macrophage polarization toward an immunostimulatory phenotype, which is linked to the establishment of an effective anti-tumor immunity (89).