Xenium in situ analysis provided high-resolution spatial gene expression data, identifying a unique population of “boundary cells” co-expressing tumor markers (e.g., ERBB2 and ABCC11) and myoepithelial markers (e.g., MYLK and DST) in the transitional zone from DCIS to the invasive tumor, suggesting their potential role in tumor progression. Here, ERBB2 is linked to neoplasm.