TLR9 and neoplasm: Abscopal responses were also reported in a clinical study of patients with low-grade B cell lymphoma treated with 2 Gy × 2 to a single tumor site that was injected with a Toll-like receptor 9 (TLR9) agonist PF-3512676, an activator of B cells and antigen-presenting cells (Brody et al., 2010).