Meirovits et al. (22) have previously shown in a cohort of 15 patients that severe mucositis correlates with elevated IL-6 levels during RT, however, 13 of the patients received 2D or 3D conformal technique radiotherapy, which is known to induce more toxicity to the oropharyngeal mucosa than IMRT. The gene discussed is IL6; the disease is mucositis.