Using a targeted RNA-seq, in OSNA remaining lysate of SLNs from Luminal A BC patients, it was found that, in macrometastatic SLNs, there were 11 upregulated genes related to tumor-microenvironment interplay: KRT7, VTCN1, CD44, GATA3, ALOX15B, RORC, NECTIN2, LRG1, CD276, FOXM1 and IGF1R. In metastatic SLNs, higher metastatic load was correlated with higher expression levels of the majority of the DEGs. The gene discussed is ALOX15B; the disease is breast cancer.