COL8A1 and gastric adenocarcinoma: In the present study, all of the 29 prognostic genes that are overexpressed in both STAD and stromal signature, unfortunately, indicated poor prognosis, among which there were several collagen-encoding mRNA such as COL1A2, COL5A1, COL5A2, COL8A1, COL10A1, and COL12A1. Through coexpression analysis, these collagens were found to be positively correlated with each other and with numerous important molecules such as LOX, MMP11, FAP, and WNT as well as macrophage M2, suggesting that collagen may play a crucial role of eliciting poor outcomes by cooperating with the above molecules in TME [24].