COL1A1 and cancer: An impressive finding of this study was that the expression of COL1A1 was positively correlated with the abundance of CAFs in almost all kinds of cancers, and macrophage infiltration in gastrointestinal cancers, BLCA, and HNSC, whereas it was negatively correlated with the quantity of CD8+ T cells in CESC, HNSC-HPV+, and SKCM, respectively.