Nevertheless, this study is strengthened by providing the first evidence of expression of both lncRNAs XIST and TSIX in lymph nodes, serum, PBMCs, and nipple discharge of BC patients correlated to PD-L1 expression in addition to excluding their hormonal dependency and finally in shedding the light upon their significant non-invasive immune biomarker role that reflects the immune checkpoint (PD-L1) expression status in BC cells, which can be further utilized in the field of personalized medicine to ascertain—with no invasive means—the eligibility of BC patients for anti-PD-L1 treatment. Here, CD274 is linked to breast cancer.