Recently, Zhang et al. (142) demonstrated in cell cultures, mouse models, and human samples the existence of a hypoxia-inducible factor (HIF)-1α/IL-1β signaling loop between cancer cells and tumor-associated macrophages (TAM) in a hypoxic microenvironment, resulting in cancer cell epithelial-mesenchymal transition and metastasis. Here, HIF1A is linked to cancer.