KRT19 and neoplasm: As validation, we performed immunofluorescence staining on tumor and normal formalin-fixed paraffin-embedded (FFPE) sections with amylase (acinar), cytokeratin-19 (ductal), Hoechst (nuclei) and Ki67 (proliferation) to evaluate co-staining patterns within individual cells (Fig. 5d, Extended Data Fig. 4a and Methods).