Hypoxia and tumor-associated macrophages: A deadly alliance in support of tumor progression

Tumor-associated macrophages (TAMs) provide a significant contribution to tumor growth and metastasis. We demonstrated the existence of two main TAM subsets, differing in activation state and localization. Of these, M2-like TAMs reside in hypoxic regions of the tumor mass and can be used as targets for hypoxia tracers. This said, hypoxia does not regulate the differentiation of TAMs but finely tunes the activity of the M2-like population.