CD3E and pneumonitis: Examination of lung tissue in irradiated C57BL/6 mice revealed that while TLY012 or ONC201 could rescue mice from radiation-induced pneumonitis (Figure 2), there was no difference in T cell infiltration as judged by the pan–T cell marker CD3ε (Supplemental Figure 4A) or the DNA double-strand break marker γ-H2AX (Supplemental Figure 4B) within lung areas deemed as normal tissue or inflamed with pneumonitis.