Histopathology analysis and cytokeratin-19 immunostaining of 3 KC metastatic tumors and of representative KCATMΔ+ (n = 6) and KCATMΔΔ (n = 5) tumors identified invasive PDAC with focal or extensive desmoplasia and variable morphology in all specimens (Fig. 1B,C). Here, KRT19 is linked to metastatic neoplasm.