Finally, we observed that the interaction between BC cell lines and PBMCs stimulates the intrinsic expression of CTLA-4, PCDC1 (PD1), CD274 (PD-L1), and PDCD1LG2 (PD-L2), which may vary depending on BC immunophenotype and time of interaction. The gene discussed is PDCD1LG2; the disease is breast cancer.