GREM1 and neoplasm: In particular, CTHRC1+GREM1+ myCAF expressed high levels of collagens (Fig. 3c, Supplementary Fig. 2B, C), including type-1 (COL1A1, COL1A6), type-3 (COL3A1), type-5 (COL5A2), and type-6 (COL6A1), which contribute to tumor cell migration and proliferation through collagen/integrin interactions31,32.