Immunohistochemistry (IHC) and RT-qPCR analysis of the tissue samples from a cohort of individuals with breast cancer obtained from Sun Yat-sen University Cancer Center (Supplementary Table 3) showed that high levels of TMUB1 and PD-L1 were significantly associated with decreased survival, and the CD8+ T cell infiltration in the patients’ tumor tissue was negatively correlated with the protein level of TMUB1 (Fig. 1e–g and Supplementary Fig. 1h). Here, CD8A is linked to breast carcinoma.