CD8A and neoplasm: Given that the abundance of FAP+CAFs in tumor tissues is positively correlated with the CD4/CD8 ratio in peripheral blood, and considering previous research indicating that Th1 and Th2 cells play markedly different roles in antitumor immunity - with Th1 cells primarily driving antitumor responses and Th2 cells facilitating immune evasion - we hypothesize that FAP+CAFs may promote the differentiation of CD4+ naive cells into Th2 cells through cytokine secretion.