Abstract Immunotherapy has transformed cancer treatment by enabling the immune system to target tumors more precisely. However, challenges such as immunosuppression within the tumor microenvironment, off‐target effects, and limited success in treating solid tumors continue to hinder its broader effectiveness. Extracellular vesicles (EVs), secreted by various cell types, have drawn increasing interest for their potential to overcome these barriers. Tumor‐derived EVs can promote immune evasion but also carry tumor antigens that stimulate immune responses. Meanwhile, EVs from immune cells, such as dendritic cells and macrophages, can enhance immune function by delivering signaling molecules that support both innate and adaptive immunity. Advances in EV engineering have further improved their stability, targeting capabilities, and therapeutic potential. This review explores the dual roles of tumor‐derived and immune cell‐derived EVs in cancer immunotherapy, discusses recent progress in EV engineering that improves their clinical utility, and evaluates their potential to augment existing immunotherapies.
Zhang et al. (2026) studied this question.