TYRP1 and neoplasm: Previously, on administering CD3xTRP1, transient T-cell activation was observed throughout the body, except for those in the tumor, which stayed activated for at least 4 days.10 This might be explained by the higher internalization rate in secondary lymphoid organs compared with KPC3-TRP1 tumors, which suggests that balancing CD3-bsAb internalization rates can help mitigate immune related adverse effects (IRAEs), while still inducing prolonged activation of antitumor T-cell responses.