CD274 and cancer: Inspired by the promising applications of self‐assembling peptides in cancer therapy, herein, we rationally designed a hexapeptide, Lys‐Phe‐Met‐Phe‐Met‐Lys (KFM), which incorporates specific amino acids to confer distinct physicochemical properties crucial for its function in PD‐L1 downregulation and localized delivery.