TLR9 and neoplasm: To address this issue, Zeng et al. fine-tuned the physical and chemical properties of polymer hybrid micelles (HMs)-two amphiphilic diblock copolymers, onto which, melanoma antigen peptides Trp2 and TLR9 agonist CpG ODN were encapsulated into sub30 nm HMs, which could expand antigen-specific CTLs drastically and provide a powerful anti-tumor effect in a lung metastatic melanoma model [99].