CD274 and breast carcinoma: Madsen et al. demonstrated a positive correlation between PI3K/AKT/mTOR pathway activation and breast cancer stemness score.492 Additionally, activation of the insulin/insulin-like growth factor signaling (IIS) pathway in breast CSCs further potentiates the PI3K/AKT pathway to sustain MYC expression, thereby enhancing the stemness traits of breast CSCs.493 Furthermore, PD-L1 contributes to the establishment of a suppressive immune microenvironment.494 Almozyan et al. revealed that the continuously activated PI3K/AKT pathway by PD-L1 is pivotal in maintaining the stemness of breast CSCs.495