Type I collagen (COL-I) is enriched in myCAF while its cognate receptor DDR1, is expressed in tumor cells, suggesting a link between myCAF and tumor cells via COL-I-DDR1 interaction, which has been verified in PDAC where COL-I-DDR1 axis orchestrates tumor growth and metastasis via regulating macropinocytosis, a nutrient scavenging pathway, and mitochondria metabolism (1, 2, 21, 47, 48). This evidence concerns the gene DDR1 and neoplasm.