IL1B and cancer: In line with the increase in IL1B observed in stage-III and stage-IV melanoma (Fig. 1 A) and a role for macrophages as the predominant source and fibroblasts as potential recipients of the cytokine signal, we found an increase in expression of the pan-macrophage marker CD68 and the cancer-associated fibroblast marker SMA in patient melanoma samples compared with normal skin (Fig. 2 A).