PDCD1 and colorectal carcinoma: Figure 5A shows that IL-15 correlated negatively with CD279 expression on T cells. These results support the opposing role of the two molecules in CRC. IL-1β levels showed a strong positive correlation with CD86 expression on peripheral blood leukocytes (Figure 5B). This could be associated with the role of IL-1 signaling in antigen-presenting cell differentiation involving the upregulation of costimulatory molecules [21].