CD4 and breast cancer: Notably, we found that in our overall cohort of breast cancers, a positive correlation was found between pSTAT1 expression and the number of all analyzed immune cell populations (CD4+: Spearman r = 0.369, P < 0.001; CD20+: r = 0.326, P < 0.001; CD57+: Spearman r = 0.188, P < 0.001).