CD4 and breast cancer: Analyses of the associations between HK2 expression and immune cells infiltration using the TIMER2.0 database (40), which showed that HK2 mRNA levels in breast cancer specimens were inversely correlated with the infiltration of CD4+ T cells (correlation: 0.184, p=4.91e-08) (Figure 4B) and CD8+ T cells (correlation: 0.166, p=1.42e-07) (Figure 4C) through TIMER algorithm and CIBERSORT algorithm analyses, respectively.