Representative image of haematoxylin–eosin staining in pre-NAC tissue in the a responder group (×100) and b non-responder group (×100). Multiplex fluorescence immunohistochemistry in pre-NAC tissue in the c responder group and d non-responder group for the following markers: CD3, CD4, CD8, CD204, FoxP3, cytokeratin and 4′,6-diamidino-2-phenylindole. Original magnification, ×20. e, f Relationship of the density of each immune cell type in the intratumoural and peritumoural areas between the responder and non-responder groups.