Umekita Y, et al. - In order to assess the prognostic significance of maspin in breast cancer patients, researchers determined maspin mRNA expression in sentinel lymph nodes (SLNs) using the remaining specimens after the one-step nucleic acid amplification (OSNA) assay. For the first time, via enrolling 93 breast cancer patients with SLNs metastasis detected by the OSNA assay, this study demonstrated maspin mRNA expression in SLNs as an independent predictor of non-SLN metastasis and the presence of ≥4 LN metastases in breast cancer patients with SLN metastasis. Hence, further progression of metastatic carcinoma in breast cancer patients with SLNs metastasis could be assessed via investigating maspin mRNA expression in SLNs using the remaining specimens after the OSNA assay.