CD274 and neoplasm: A multifunctional “drug‐like” copolymer with the auto‐changeable upper critical solution temperature and selective depletion of reduced nicotinamide adenine dinucleotide phosphate (NADPH) inside tumor cells is synthesized and employed to develop a multifunctional nanomedicine (BMS202@HZP NPs), which sensitizes the low‐dose radiotherapy and achieves the radio‐immunometabolism regulation against triple‐negative breast cancer (TNBC), providing a promising strategy to reinforce anti‐PD‐L1 against TNBC.