Across the six ductal cell subclusters, we observed an opposite trend of gene expression between proliferating markers (e.g., MKI67) and malignant metastatic markers (e.g., CEACAM5/6 and KLK7) (Fig. 3a), suggestive of orchestrated differentiation of tumor cells during metastasis. The gene discussed is KLK7; the disease is neoplasm.