Instead, the current focus is on combining systemic mechanism-based therapies (eg, epidermal growth factor (EGF) receptor tyrosine kinase inhibitors/immunotherapies) with radiotherapy.7, 8 Although combination trials are promising, they are equally challenging because of the potential for acute and late severe toxicities, particularly pneumonitis and esophagitis.9 The gene discussed is EGF; the disease is pneumonitis.