PDCD1 and neoplasm: The engineered platelets were used to generate platelet‐derived microparticles to facilitate binding between anti‐PD‐L1 and tumor cells, which further reduced postsurgical tumor recurrence and metastasis.181 The same group conjugated anti‐PD‐1‐decorated platelets to hematopoietic stem cells (HSCs) for the treatment of acute myeloid leukemia.