CD19 and breast cancer: In an analysis of the association of CD45+ tumor-infiltrating leukocytes (CD8+ T cells, CD19+ B cells, CD56+ NK cells and CD68+ macrophages) and the cSERPINE2 level in breast cancer tissues (n = 27), immunohistochemistry (IHC) staining suggested that higher cSERPINE2 expression was notably associated with increasing CD68+ macrophages infiltration (Fig. 2c, d).