In BC, CAF-S4 presence correlates with worse OS and the development of liver metastasis [178]; further, CAF-S1 is associated with reduced infiltration of CD8+ cells, a significant attraction of FOXP3+ CD4+ regulatory T cells [177,179], and the expression of CD73, which could mediate its immunosuppressive activity [179]. The gene discussed is CD8A; the disease is breast cancer.