CCL20 and neoplasm: Following local injection, anti‐PD‐L1‐DOX‐R848‐MIP‐3α/thioketal nanoparticle (TKNP) converts tumor cells to a vaccine owing to the combinatorial effect of DOX‐induced ICD, R848‐mediated immunostimulatory properties, and MIP‐3α‐induced immune cell recruitment in the tumor microenvironment.