CD4 and neoplasm: It revealed that, (1) global characteristics of systemic anti‐tumor immune response induced by MWA in the treatment of breast cancer was firstly reported; (2) B cells were important antigen‐presenting cells (APCs) that initiate CD4+T cells in MWA‐induced immune response; (3) based on the comprehensive characteristics of MWA‐induced response, we found that immune checkpoint inhibitors synergistically activated peripheral T cells after MWA in vitro.