The highest expression of genes encoding Col1a1-2, Col3a1, Col4a1, Col4a2, Col5a1, Col5a2, Col6a1, Col8a1, Col9a3, Col10a1, Col12a1, Col14a1, Col15a1, Col16a1, Col18a1, and Col28a1 were detected in untreated tumors (Fig. 6c and d), whose landscapes were dominated by Krt8+ cancer cells. Here, COL4A1 is linked to cancer.