Additionally, the expression of COL5A1 [collagen type V alpha 1 chain and a fibroblasts hallmark gene (13)] was upregulated in cancer tissues compared to that in NP and ATT (Figure 1J); however, IGFBP5 (insulin like growth factor binding protein 5), a protein secreted by CAFs (14), was highly expressed in TS (Figure 1K). Here, COL5A1 is linked to cancer.