CD274 and breast carcinoma: Son et al. (2022) found that PD can inhibit VEGF-induced angiogenesis by blocking the activation of mitogen-activated protein kinases and the production of IL-8. Excessive neutrophils facilitate breast cancer growth and pulmonary metastasis. Increased PD-L1 inhibits spontaneous apoptosis of neutrophils. Ye et al. (2023) found that PD inhibits the expression and positive rate of PD-L1 in neutrophils to induce neutrophil apoptosis and decrease their high migratory capacity.