CD4 and breast cancer: The findings revealed that KLF2 expression level had a positive association with the infiltrating levels of CD8+ T cells (r = 0.11, p = 5.52E-4), CD4+ T cells (r = 0.219, p = 5.90E-12), macrophages (r = 0.148, p = 3.17E-2), neutrophils (r = 0.064, p = 4.94E-2), and dendritic cells (DCs) (r = 0.098, p = 3.17E-3) in breast cancer samples (Figure 5A).