Fig. 1

PD-L1 immunohistochemical and in situ mRNA expression in TNBC tissues. a PD-L1 negative expression with IHC detection (×200), b PD-L1 negative expression with in situ mRNA hybridization (×200). c Expression of PD-L1 protein in tumor cells (score as 3+) (×200). d In situ mRNA expression of PD-L1 is indicated by brown staining in tumor cells (×200). e Expression of PD-L1 protein in immune cells (score as 3+) (×200). f In situ mRNA hybridization of PD-L1 is indicated by brown staining in immune cells (×200)