CD8A and cancer: Accordingly, increased protein expression levels of the CCL4-regulating protein β-catenin and low mRNA levels of CCR5 in CRC tissue turned out to be associated with decreased numbers of tumor-infiltrating CD8+ T cells [33,48] and, moreover, low CCL4 protein expression levels in colonic tumor tissue were associated with a significantly decreased cancer-specific survival rate in CRC patients [21].