B2M and breast cancer: Fourth, β2M is positively correlated with p-CREB, p-SGK1, and Bcl-2 and has no correlation with HIF-1α, VEGF and p-ERK1/2, and p-SGK1 has a significantly positive correlation with Bcl-2 in cancer tissues of patients with luminal A breast cancer, which agrees with the results obtained from the same molecular types of breast cancer cells except CREB signaling.