Analysis of let-7a and CCR7 expression in tissues from 15 breast cancer patients (five infiltrating ductal cancers (P1, P3, P11-13), one metaplastic cancer matrix-producing type (P2), seven invasive ductal cancers (P4-10), one infiltrating cribriform cancer (P14), and one atypical medullary cancer (P15)] (Table 1). (a) Let-7a expression levels were determined by using real-time RT-PCR in malignant tissues (T) and their normal counterparts (N) from breast cancer patient tissues. RNU6B was used as a normalization control. (b) CCR7 expression in both malignant and normal tissues was detected by using Western blotting. β-actin was used a normalization control.