CD4 and breast cancer: To gain more insight into potential associations between tumor LDHC expression and immune cell infiltration, we applied the Tumor IMmune Estimation Resource (TIMER) algorithm to estimate the relative abundance of six major immune cell types (B cells, CD8 + T cells, CD4 + T cells, macrophages, neutrophils and dendritic cells) in the TCGA breast cancer dataset (Fig. 1A).